Banana-Raspberry Cake with Lemon Frosting

Covered with lemon-cream-cheese icing and a layer of fresh raspberries, this puff pastry cake is juiced with mashed ripe bananas.
Preheat the oven to 350 degrees.To prepare the cake, brush 2 (8-inch) round cake pans with cooking spray; line the bottom with waxed paper. Brush waxed paper with cooking spray; sprinkle each pan with 1 1/2 teaspoons flour.Put the granulated sugar and 1/4 cup butter in a large bowl; beat with a mixer on medium speed until smooth (about 3 minutes). Add the eggs, 1 at a time, beating well after each addition.Lightly pour 1 3/4 cups flour into dry measuring cups and smooth with a knife. Combine the flour, baking powder, and 1/2 teaspoon salt, mixing well with a whisk.Combine buttermilk, banana, and 1 teaspoon vanilla. Add the flour and buttermilk mixture alternately to the sugar mixture, starting and ending with the flour mixture (mix after each addition until smooth). Pour the batter into the prepared molds.Bake the cake at 350 ° C for 25 minutes or until a wooden stick inserted in the middle comes out clean. Cool in the pan for 10 minutes on a wire rack; remove from the pan. Remove the wax paper. Cool the layers completely on a wire rack.To make the frosting, combine the cream cheese, 2 tablespoons butter, zest, 1/2 teaspoon vanilla, and a pinch of salt in a large bowl. Beat with a mixer on high speed until fluffy. Gradually add the powdered sugar; beat on low speed until smooth (do not interrupt).Place 1 cake on a plate and spread with 1/3 cup icing. Place the raspberries in a single layer on top of the icing, and top with the remaining cake. Spread the remaining icing on the top and sides of the cake. Keep the cake loosely covered in the refrigerator. Garnish with fresh raspberries if desired.