Blueberry season here is just ending, much to my disappointment. My favorite u-pick farm is closing up this weekend. I went about every other weekend for the past two months. Before they opened, they sold their berries at local farmer’s markets, and as soon as they started I rushed out to purchase a few cartons. I wanted my favorite berries for this cake, even if they were used only for a garnish. My husband liked eating slices of the cake with even more berries on the side. The fresh blueberries really went well with the lime in the cake.
adapted from Cooking Light, June 2006
- For the filling: Combine lime zest, lime juice, and condensed milk in a bowl. Cover and chill for at least 3 hours.
- For the cake: coat the bottoms of 3 (8-inch) round cake pans with cooking spray; line bottoms with wax paper. Coat wax paper with cooking spray; dust with flour.
- Combine cake flour, 1 cup sugar, baking powder, and salt in a large bowl, stirring with a whisk until well combined. Combine oil, 1/3 cup juice, 3 tablespoons water, 1 teaspoon rind, lemon extract, and egg yolks in a medium bowl, stirring with a whisk. Add oil mixture to flour mixture; beat with a mixer at medium speed until smooth.
- Place egg whites in the bowl of a stand mixer; beat at high speed until foamy. Add cream of tartar; beat until soft peaks form. Gradually add remaining 1/4 cup sugar, 1 tablespoon at a time, beating until stiff peaks form. Gently stir one-fourth of egg white mixture into flour mixture; gently fold in remaining egg white mixture.
- Divide cake batter equally among prepared pans, spreading evenly. Break air pockets by cutting through batter with a knife. Bake at 325° for 20 minutes or until cake springs back when lightly touched. Cool in pans for 10 minutes on a wire rack; remove from pans. Remove wax paper from cake layers. Cool completely on wire rack.
- For the butter cream: Place sugar and egg whites in the bowl of a stand mixer. Place the bowl over a pot of simmering water. Heat, whisking constantly, until the mixture reaches 160°F. Mixture will be frothy.
- Remove bowl from heat and attach to the mixer. Fit the mixer with the whisk attachment. Beat on medium-high until stiff peaks form, about 10 minutes. The mixture should be room temperature. Reduce speed to medium and add the butter, 2 Tbs at a time, making sure each addition is well incorporated. If the mixture is soupy, stick the bowl in the fridge, chill for 15-20 minutes, and continue to beat until the mixture comes together. If the mixture looks curdled, just keep beating. Beat in the vanilla.
- To assemble the cake, place one cake layer on a serving plate. Spread half the lime filling on top. Place second cake layer on top of the first. Repeat with remaining filling and final cake layer. Frost cake with butter cream.