Rainbow Layer Cake

Step 1
Preheat the oven to 350 degrees F (175 degrees C). Grease two 8-inch round cake pans.

Step 2
Combine cake mix, eggs, water, and oil together in a large bowl. Beat using an electric mixer on medium speed for 2 minutes.

Step 3
Split the batter into 6 different bowls and add a different food coloring to each bowl. Pour about 1 cup of each of the batters into the first pan in this order: red, orange, yellow, green, blue, and purple, right on top of one another in the center of the pan. Pour about 1 cup of each batter in the same manner into the second prepared pan in reverse order: purple, blue, green, yellow, orange, and red; you do not need to swirl the colors around at all.

Step 4
Bake in the preheated oven until a toothpick inserted into the center of the cakes comes out clean, 34 to 38 minutes.

Step 5
While cakes bake, beat cream cheese, butter, lemon juice, and vanilla extract for filling together using an electric mixer. Beat in powdered sugar until combined.

Step 6
Beat heavy cream for frosting using an electric mixer until almost stiff; add powdered sugar and vanilla extract. Beat until cream holds peaks.

Step 7
Remove cakes from the oven and let cool completely in a refrigerator, about 30 minutes.

Step 8
Spread filling on the top of the bottom cake layer; top with the top layer of cake. Frost and decorate as desired. Keep cake refrigerated.