It is officially spring. Although the weather has been inconsistent throughout the year, I am ready for spring. Although Mother Nature may not cooperate immediately, this is the best time to embrace pastels in all their glory. There are many occasions to enjoy the beautiful spring colors, lush florals from Easter to Mother’s Day, and baby and bridal showers. Today’s Blackberry Lime Cake is a great example.
This cake celebrates all things spring. As sweetened blackberries are infused with subtle lime notes, shades of violet sing. We decorate with beautiful edible flowers and tint the frosting with the natural pigments found in fresh blackberries. It creates a subtle lavender hue, which looks like it’s from a bottle but results from the earth’s bounty.
Because of their high water content and large size, fresh blackberries are not often used in cake baking. A pack of fresh blackberries can be tossed into a buttercream frosting to make a soupy mess. If you add them, fresh berries will sink to the bottom of the cake batter. We are taking fresh berries and reducing their volume. Once it has been set, the result looks almost like a paste. It clumps slightly when mixed with our frosting. This gives the cake a beautiful speckle that resembles bits and pieces of broken berries.
The result could be more tart or sweet. It’s a delicate, mild blackberry that you can eat. To amp up the blackberry flavor, cut some berries in half and add them between the cake layers. You can go big or keep it mild. This one is worth your time.
Make the Blackberry Lime Cake
Preheat oven to 350F. Three 8-inch round pans should be buttered and lightly floured. Line the pans with circles of parchment paper.
Mix flour, baking powder, and baking soda. Blend flour with the zest of limes. Set aside.
Combine milk and lime juice in a small bowl. Mix well and let cool. This process is similar to making homemade buttermilk.
Use the paddle attachment to beat butter and sugar in a bowl with a stand mixer. Beat on medium-high speed until light and fluffy, approximately 3 minutes.
Mix on low and add eggs one by one. After each egg, mix well.
Mix in vanilla extract.
Mix the flour mixture with the milk in three batches. Start and end with the flour mixture. Stay undermixed. Stop the mixer, and clean the bowl and blade of the mixer.
Divide the batter equally between the three 8-inch round pans.
Bake for 25-27 mins or until a toothpick inserted in the center comes clean.
Allow cooling in the pans for 5-10 minutes. Then, transfer to a wire rack to complete cooling.
Take the Blackberry Reduction!
Mix blackberries, sugar, and lime juice in a saucepan over medium heat.
Allow the juices to bubble for 10 to 15 minutes or until the berries are soft and easy to smash with a spoon.
To remove seeds, strain the mixture using a fine mesh strainer. Use the back of a wooden spoon to get as much pulp as possible. To remove all the blackberry pulp, scrape the bottom of the filter. Remove the seeds and return the strained puree to the saucepan.
It is stirred with a wooden spoon until the sauce is reduced to a few tablespoons. This should take approximately 10 minutes.
Place in a bowl. Cover with plastic wrap. Push the plastic down to get the Blackberry reduction. Let cool.
Make the Blackberry Buttercream
Mix sugar and egg whites in a bowl with a stand mixer. Whisk until well combined.
Place the bowl on top of a saucepan of simmering water to create a double boiler. Mix the egg mixture constantly until it registers 160° on a candy thermometer. Transfer the bowl to the stand mixer.
Use the whisk attachment to beat the egg white mixture for 8-10 minutes on high speed until it is no longer warm to your touch. The meringue should be stiff and glossy, and fluffy.
Move to the paddle attachment. Mix the cubed butter slowly into the mixer and mix until well combined.
Mix in vanilla extract. Whip on medium-high for 3 to 5 minutes until smooth and silky.
Mix in the blackberry reduction. Whip again until well combined. The buttercream can be broken. Continue to mix until the buttercream is smooth.