Camp and kitsch are always welcome in my kitchen, so long as flavor isn’t sacrificed (however, other sacrifices are fine… mwahaha), and this one takes the cake.
The colors of this Spooky Blackberry Cake just shriek “Halloween!” to me. Sure, it’s not orange and black, but purple and green are almost secondary colors to the holiday in my book—kind of like gold and silver are to the red and green of Christmas. Maybe it’s the green of the Wicked Witch’s skin and the purple of her brew; maybe it’s the color scheme of cartoon Frankenstein (or, more accurately, his monster); or maybe it’s the triad that orange, green and purple create on a color wheel that make these colors so striking for Halloween, but there’s something arguably creepy, and undeniably campy about colors so gauche. The color palette of Halloween is just as shockingly neon as it is darkly malevolent—it’s as much about the living as it is the dead.
Much as I love all things camp I can’t, as I’ve said, entirely forgo flavor for the sole sake of it. Even the great Edward D. Wood Jr. didn’t schlock up his films for the gratuitous sake of being gratuitous—although, that’s a whole different story. This cake has incredible flavor. The cake itself is flavored with blackberry, and boy is it ever, while the buttercream is a sharp shock of lime. You may not think of blackberry and lime as Halloween flavors, but think of it as a fresh version of sweet-and-sour candies in cake form.
It gets its blackberry flavor from a combination of heavily reduced blackberry puree, and a little bit of blackberry extract. Normally I’m not a fan of flavorings and extracts being used as an actual flavoring device—even the best of the best vanilla extract can be, if leaned on too much, off-putting—but this one is impressive. Minimal amounts of it actually taste like real, fresh blackberries; with actual blackberries the flavor is amplified tremendously. It can be tough adding fruit purees to cakes; it can throw off the pH causing it to not rise properly, or the flavor can get lost. The first bite of this cake and there’s no question—it’s blackberry. There’s nothing to stop you from making this cake in the summer when blackberries are more in season, but frozen work just as well (I actually rely heavily on a stash of bags of them I have in the freezer from when they were in season); you’re going to cook them down anyway.
The cake is frosted with an Italian buttercream that’s flavored with lime. This is not the typical American buttercream, which is nothing more than copious amounts of powdered sugar beaten into soft butter; Italian buttercream differs vastly. That’s not to say it’s complicated or difficult, it just a little time and comes with a bit of waiting around. You start by heating together corn syrup and sugar in a saucepan over medium heat until it melts, and reaches 240°. Use a saucepan that fits everything adequately because you cannot stir it to combine, so just swirl and shake the pan gently—as the corn syrup heats and loosens a bit it’ll moisten the sugar granules.
Meanwhile, you whip egg whites in a stand-up mixer until you have stiff peaks—don’t over whip them to the point where they get dry, though—at which point you add fresh lime zest to the readied and bubbly syrup, and very slowly, VERY carefully pour the whole thing into the egg whites, machine whipping all the while. They’ll thicken and go glossy, looking like the most flawless meringue you’ve ever seen, save for a few flecks of green of course. This has to beat for a long while on medium until it cools down to about 70° (or no more than 75°). I’ve read countless recipes that clock this in at around 10 minutes—out of all the times I’ve made Italian buttercreams, never has it cooled even remotely close to 70° within 10 minutes, so play on 15 – 20 minutes. It is crucial that that it cool down to this because you’re going to add a truly sinister and sinful amount of softened butter. If the egg whites are too hot, the butter will melt and the frosting will get oily and running, turning the frosting to a liquid vat of something similar to melted ice cream, and there’s no coming back from that. Once it has devoured all the butter, it gets a final spike of lime juice to help counter the sweet richness of the frosting.
The whole thing gets covered in blackberry drip. It’s basically a doctored up royal icing, but it really drives the point home… or you could say, it’s the final nail in the coffin. It’s best to chill the frosted cake a bit before cascading the drip; it helps the drip to solidify a little quicker and gives it something to cling to.
As you’ve probably noticed, there’s a fair amount of food dye here. Outside of red velvet or royal icings, I don’t normally go for dying and coloring—I’m perfectly happy with my Lemon Cheesecake being deceptively pail, or my Margarita Cheesecake lacking the certain electric shock to your retinas that you’d get from its namesake—but given that it’s Halloween, a time of year where, all serious traditions aside, we worship the Dayglo rainbow of sugar filling our little plastic Jack-O-Lantern buckets to the brim, I make an exception. It is important that you use gel paste or liquid gel dyes; the usual liquid dyes in those teardrop-shaped bottles that many of us grew up with are less intense in color so more is needed to get a good color and, because they’re water-based, it can water down your cake or frosting. The gel dyes, be it liquid gels (usually in little squeeze bottles) or gel pastes, are very concentrated in their color and contain little water so they alter the recipe much less if at all. Just mix the purple into the milk and the green into the lime juice until they dissolve completely (no little bits, flecks, chunks) for the cake and frosting respectively. It can be tricky to add the dye into the batter without dissolving it in a liquid first, as they are very thick and tend to not mix into things evenly, so you want to try to get the color as close to what you want initially.
One look at this cake and your eyeballs will pop right outta their sockets. Cut it open and the shock will make your head explode! Take a bit and whatever is left of your face will melt right off! It’s awesome—you’re going to love it. So give it a try this Halloween… or else!
Go into the light and follow me on BLOGLOVIN’ (Carol Anne!)
| Servings | Prep Time |
| 10 more or less | 1.5 hours |
| Cook Time | Passive Time |
| 45 minutes total | 2 hours to cool cakes, plus more for frosting |
|
|
|
|
A cake that tastes like biting into a fresh blackberry, and the sharpest, limiest buttercream. It's campy, spooky, weird... perfect for Halloween!
|
- 3/4 cup butter softened at room temperature
- 1-1/2 cups sugar
- 4 eggs room temperature
- 2-1/4 cups flour all-purpose
- 2 tablespoons cornstarch
- 2-1/2 t-spoons baking powder
- 1/4 t-spoon cream of tartar
- 1/4 t-spoon kosher salt
- 3/4 cup whole milk room temperature
- 6 ounces blackberries fresh or frozen
- Scant 1 tablespoon water
- 1/2 t-spoon blackberry extract (see note)
- 1/4 t-spoon vanilla extract
- 5 or so drops electric/neon purple gel food dye
- Butter and flour for greasing cake pans
- 7 egg whites
- 1/2 t-spoon cream of tartar
- 2 cups sugar
- 2/3 cup light corn syrup
- 1 tablespoon lime zest, finely grated from about 4 - 5 limes
- 4-1/2 sticks butter softened at room temperature (1.125 pounds/1 pound, 1 ounce)
- 1 tablespoon lime juice freshly squeezed
- About 3 - 5 drops electric/neon green gel food dye
- Lime juice or wedges for degreasing mixing bowl and whisk
- 6 ounces blackberries fresh or frozen
- 1 tablespoon water
- 3 cups powdered sugar sifted
- 2 tablespoons meringue powder
- 1 t-spoon lime juice freshly squeezed
- A few drops electric/neon purple gel food dye
- water as needed
- Preheat the oven to 350° Lightly grease two 9” round cake pans with butter and dust with a little flour, shaking off the excess.
- Put the blackberries and water in a small saucepan, cover and place over medium-low heat and cook for about 5 – 7 minutes, until they fall apart. Squish them completely with a potato masher or puree it in a mini food processor, and strain through sieve—you should have about ½ cup. Return the juice to the pan and reduce over low down to ¼ cup. Set aside to cool.
- Sift the flour, cornstarch, baking powder, cream of tartar and salt together into a large bowl and set aside, too.
- Meanwhile, cream the butter and sugar in a stand-up mixer with the paddle attachment on medium speed for 3 minutes, until it’s light, pale and fluffy.
- Crack the eggs into a liquid measuring cup and turn the mixer on medium-low. Add the eggs one at a time and let them fully incorporate and emulsify before adding the next. Shut the mixer off immediately once the final egg is mixed in, and scrape the bottom and sides of the bowl with a rubber spatula.
- Mix the food coloring into the blackberry puree until it breaks up completely and dissolves. Beat in the milk and extracts.
- Turn the mixer back on low and add about a third of the dry ingredients and let them incorporate before pouring in about a third of the wet ingredients. Do this twice more, ending with the wet. Scrape the bowl and mix just until everything is combined. Do not over mix.
- Turn out the batter into the prepared cake pans and bake for 30 minutes in your preheated oven. The cakes will be set and almost firm to the touch, but not tough, and will have begun to pull away from the sides of the pan ever so slightly—this is not a sign of over-baking here.
- Let the cakes cool in their tins for about 10 minutes before inverting them onto a greased wire cooling wrack until completely cooled.
- Combine the sugar and corn syrup in a saucepan (about a quart in volume) and place over medium heat. Dip in a candy thermometer and bring it to a boil, keeping it there until it reaches 240°.
- Zest the limes over a ceramic plate (a wood cutting board would absorb much of the flavor) and set aside.
- Wipe down the inside of the standup mixer’s bowl and whisk attachment with a little lime juice and paper towel to ensure they’re both free of grease. Add the egg whites and cream of tartar and beat on high speed for about 3 minutes, until big full peaks form (but without becoming dry).
- The syrup should be just under 240°; add in the lime zest and stir once or twice just to combine a little. Once it reaches 240° turn off the heat and immediately pour it into the egg whites. Pour it in a slow, even stream in between the inside of the bowl and the whisk, being extremely careful not to get any on yourself or the whisk (it can fling hot syrup everywhere).
- Keep the mixer on high, whisking until the whites and bowl are completely cooled to at least 70 - 75°. This can take about 15 minutes, more or less, depending on the temperature of your kitchen.
- Once it’s completely cooled turn the mixer on medium and add the soft butter, about a third of a stick at a time, letting each piece incorporate almost completely before adding the next.
- Mix together the lime juice and food dye until there are no clumps and, once all of the butter has been beaten in, pour in the brilliant green juice. Beat until the buttercream is electrified by neon green.
- For the blackberry drip, boil, puree, strain and reduce the blackberries the same way as before until you have ¼ cup.
- Sift together the powdered sugar and meringue powder into a mixing bowl.
- Stir the food coloring into the puree and pour it all into the sugar-meringue bowl with a spritz of lime. Whisk until combined. The drip should be thin enough to spread easily and drip down the sides of the cake, but thick enough not to run off the cake. Add water, as needed, to thin it out drop by drop.
- Put a small spoonful of the frosting in the center of a cake stand and set the first layer of cake on it, flat side facing up. Spread about a cup or so of frosting on the top and then set the other layer on top of that, again with the flat side facing up.
- Coat the top and the sides in a layer of frosting to crumb coat, scraping off the access buttercream. Stick the cake in the fridge for a few hours to chill the frosting (it will make it easier to apply the final layer of buttercream).
- Once the crumb coat is firm, frost it with the remaining frosting (though you may not want to use all of it). Chill it again for a little bit before pouring the blackberry drip over it (once it hits the cold icing it firms up much quicker). Serve it immediately or give the drip a chance to set up.
- The blackberry extract that I use is by LorAnn Oils from King Arthur Flour. It tastes just like fresh blackberries in minimal amounts, but be conservative when using it; it can go from fresh berries to fake candy flavor with just a drop.
- Depending on how much of a drip you want on the cake you may not need it all (I usually end up with about a quarter of it left over).