Blackberry Lime Italian Soda Cake
Light and fluffy lime cake layers with whipped cream filling, blackberry lime compote and blackberry lime buttercream.
Ingredients
FOR THE CAKE
- 3 cups (345 g) cake flour
- 1 tablespoon (14 g) baking powder
- 1 tablespoon lime zest
- 3/4 teaspoon (4 g) salt
- 1 cup (226 g) unsalted butter, at room temperature
- 1 3/4 cups (350 g) granulated sugar
- 6 egg whites, at room temperature
- 1 1/4 cup (240 g) buttermilk, at room temperature
- 1/4 cup fresh lime juice
FOR THE COMPOTE
- 3 cups (360 g) blackberries
- 1/2 cup (100 g) granulated sugar
- 1 tablespoon (8.12 g) cornstarch sifted
- zest of one lime
FOR THE BUTTERCREAM
- 2 cups (452 g) unsalted butter, slightly chilled
- 6 cups (750 g) powdered sugar, measured and then sifted
- 1/2 cup (115 g) strained blackberry compote, to remove any seeds
- 3 tablespoons (43.3 g) heavy whipping cream
- 1 teaspoon (4.2 g) vanilla extract
- pinch of salt
- *This buttercream recipe makes enough to fill and cover your cake. If you want to add additional piping, you’ll want to make an extra 1/2 batch.
For the Whipped Cream
- 1 cup (240 g) heavy whipping cream, cold
- 1/2 cup (62.5 g) powdered sugar, sifted
- 1/2 teaspoon (2.1 g) vanilla extract
- 1 tablespoon E-Z Gel
Instructions
FOR THE CAKE
- Preheat the oven to 325 degrees F. Spray three 8-inch round cake pans with nonstick spray. Line the bottom of each pan with parchment paper, then spray the pans again.
- Combine the flour, baking powder, lime zest, and salt into a medium mixing bowl and whisk to combine. Set aside.
- In the bowl of an electric mixer, combine the butter and the sugar. Beat until light and fluffy, about 3 to 5 minutes.
- Gradually add the egg whites, making sure to mix well between each addition, being sure to scrape down the sides and bottom of the bowl as you go along. Once all of the egg whites are added, mix for an additional 3 minutes, until the mixture is lighter in color and smooth in texture. You'll also notice the volume increases.
- While the butter, sugar, and eggs mix, stir together the buttermilk and lime juice.
- Turn the mixer to low speed. Alternately add the flour mixture and the buttermilk mixture, starting and ending with the flour mixture. Stir just until combined.
- Divide the pans evenly between the three cake pans, about 16 ounces in each pan. Bake the layers for 25 to 30 minutes, or until a toothpick inserted in the center of the cake comes out with a few moist crumbs on it.
- Allow layers to cool in the pans for about 15 minutes before inverting them onto cooling racks to cool completely. Wrap in plastic wrap and chill until ready to use. If you need to level the cake layers, be sure to do that BEFORE you freeze them.
FOR THE COMPOTE
- Combine the blackberries, lime zest, and sugar in a medium saucepan over medium heat. Stir the mixture while bringing it to a boil and occasionally breaking up the berries to release their juices.
- Add the cornstarch.
- Let simmer for about 10 minutes until the mixture is reduced by half. (We're trying to reduce the amount of water and thicken the mixture.)
- If needed, to remove any larger pieces of blackberries, you can puree the compote in a food processor or blender. Just be sure to let it cool a bit before you do.
- Strain 1/2 cup of the mixture and reserve for frosting. Refrigerate the strained blackberry mixture and the remaining compote for at least 4 hours before using.
FOR THE BUTTERCREAM
- In the bowl of a stand mixer fitted with the paddle attachment cream the butter on medium speed for about 3 minutes, until the mixture is light and fluffy.
- With the mixer on low speed, slowly add the powdered sugar, followed by the strained blackberry compote, heavy cream, vanilla extract, and pinch of salt.
- Continue to beat the frosting on medium-high speed for an additional 5 minutes.
- Before frosting your cake, mix the frosting by hand with a wooden spoon to push out the air pockets. This will also help the frosting pull back together if it looks separated from adding the blackberry juices.
For the Whipped Cream
- Combine the heavy whipping cream, E-Z Gel, powdered sugar, and vanilla in a chilled stainless steel bowl. Beat the mixture with the whisk attachment until stiff peaks are formed. Refrigerate until ready to use.
ASSEMBLY
- Spread a dollop of frosting on a cake board or cake plate to hold the first cake layer in place.
- Place the first cake layer, top side up, on the cake board and pipe a rim of blackberry frosting around the edges to act as a barrier to the compote. Spread half of the whipped cream over the cake layer, followed by about 1/3 cup of the blackberry compote.
- Top with the next cake layer and repeat step 2.
- Place the final cake layer top side down. Apply a thin layer of buttercream around the entire cake to lock in the crumbs. Freeze the cake for about 10 to 15 minutes to set the crumb coat.
- Continue frosting your cake, making sure to stir the buttercream with a wooden spoon to push out any air pockets.