Citrus Mousse Cake With Buttercream Frosting Recipes

CITRUS MOUSSE CAKE WITH BUTTERCREAM FROSTING

Steps:

• Preheat oven to 325 degrees. Butter two 8-by-2-inch round cake pans. Line with parchment; butter parchment. Dust with flour, tapping out excess.
• Whisk together flour, baking powder, baking soda, and salt until thoroughly combined, 30 seconds. Beat butter with sugar and zest until light and fluffy. Beat in eggs, one at a time, thoroughly combining after each addition and scraping down bowl as needed. Beat in lemon juice. With mixer on low, add flour mixture in 3 batches, alternating with buttermilk and beginning and ending with flour.
• Divide batter evenly between prepared pans, smoothing tops with an offset spatula. Bake, rotating pans halfway through, until tops spring back when lightly touched and are light golden, about 1 hour, 10 minutes. Transfer pans to wire racks; let cool 10 minutes. Turn out of pans, remove parchment, and let cool completely, about 2 hours. Cakes can be made to this point and refrigerated, well wrapped in plastic, up to 1 day.
• Trim tops of cakes flat. Split each cake horizontally into 3 equal layers. Line an 8-inch cake pan with 2 parchment strips, leaving a 3-inch overhang on all sides. Place 1 cake layer in pan, bottom-side down. Spread 1 cup mousse evenly over it; top with a second cake layer. Repeat, spreading 1 cup mousse between each layer. Finish with a cake layer, bottom-side up. Refrigerate, covered in plastic, at least 1 hour and up to overnight.
• Turn cake out of pan onto a cake plate. Spread 1 cup buttercream evenly over top and sides to create a crumb coat. Refrigerate 15 minutes. Spread remaining 3 cups buttercream over top and sides. Decorate as desired.

CITRUS MOUSSE FILLING

Steps:

• Sprinkle gelatin over 2 tablespoons cold water; let stand until soft, about 5 minutes. Meanwhile, in a medium saucepan off heat, whisk together 1 cup granulated sugar, zest, and egg yolks. Whisk in lime and lemon juices and salt. Add butter; place over medium-high heat. Cook, whisking constantly, until butter has melted, mixture is thick enough to coat the back of a spoon, and small bubbles form around edge of pan, about 5 minutes. Stir in gelatin mixture; cook until completely dissolved, about 1 minute more.
• Pour curd through a fine-mesh sieve into a nonreactive bowl. Press plastic wrap against surface of curd; refrigerate until cold, about 1 hour (or stir over an ice bath until chilled, about 15 minutes).
• 3. Whisk cream with confectioners' sugar until stiff peaks form. Whisk curd briefly to loosen, then fold in whipped cream. Beat egg whites with whisk attachment until soft peaks form, then gradually beat in remaining 1/4 cup granulated sugar until stiff peaks form. Gently fold into curd mixture. Refrigerate in an airtight container at least 1 hour and up to 2 days.