Peanut Butter and Jelly Cake

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Lightly grease two 8-inch square baking pans with baking spray. Line the bottom of each pan with a square piece of parchment paper. Spray parchment with baking spray, then flour each parchment-lined pan, shaking away any excess flour.

Step 2
Whisk cake flour, baking powder, and salt together in a medium bowl; set aside.

Step 3
Combine sugar and butter in a large mixing bowl; beat with an electric mixer at medium speed until light and fluffy, 3 to 5 minutes. Add vanilla extract. Add the flour mixture, alternately with the milk, with the mixer running on low speed, beginning and ending with the flour.

Step 4
Beat egg whites in a clean mixing bowl at medium speed until stiff peaks form. Gently fold egg whites into the batter. Divide the batter evenly between the prepared pans.

Step 5
Bake in the preheated oven until a toothpick inserted into the center of the cakes tests clean, 30 to 35 minutes. Cool the cakes in the pans on a wire rack for 15 minutes. Run a knife around the edge of the pans and turn cakes out onto the wire rack. Remove parchment paper and cool completely, about 1 hour.

Step 6
Working on one at a time, transfer cakes to a large cutting board or work surface. Trim the golden brown, rounded top off of each cake using a large serrated knife. Slice each cake in half horizontally to yield 4 slices.

Step 7
Prepare the filling: beat peanut butter, cream cheese, honey, butter, and salt together at medium speed until smooth. Beat in powdered sugar, 1/2 cup at a time, until smooth. Beat in milk, 1 tablespoon at a time, until desired consistency is reached. The peanut butter mixture should be loose enough to be spreadable.

Step 8
Place jelly in a small mixing bowl and whisk to loosen.

Step 9
Carefully transfer one cake layer to a cake plate or serving platter. Gently spread 1/3 of the peanut butter mixture over the cake, spreading all the way to the edges. Spread 1/3 of the jelly over the peanut butter layer. Place the second cake layer on top and repeat with peanut butter filling and jelly. Repeat with the third layer, remaining filling and jelly. Place the final cake layer on top, trimmed side up. Slice diagonally for a sandwich effect.