Preheat oven to 350°F. Spray two 8-inch round cake pans with nonstick spray and line the inside bottom of each pan with parchment paper. Set aside.
Place the cake mix in a large bowl and set aside.
26.5 ounces white cake mix
In a medium bowl, using a hand mixer, beat the buttermilk, eggs, vegetable oil, white vinegar, vanilla extract, and pink gel food coloring together on low speed just until mixed.
1½ cups buttermilk, 3 large eggs, ½ cup vegetable oil, 1 tablespoon white vinegar, 2 teaspoons pure vanilla extract, 1-2 drops pink gel food coloring
Pour the wet mixture into the cake mix and beat on a low speed just until mixed. Use a spatula to scrape down the sides of the bowl.
Divide the cake batter evenly between both prepared cake pans (about 691 grams per pan).
Bake in the preheated oven for 33-35 minutes, or until a toothpick inserted in the middle comes out clean.
Remove the cakes from the oven and let them cool in the pans for 15 minutes before removing and cooling completely on wire racks.
Once cakes have cooled to room temperature, wrap each cake layer separately in food-safe plastic wrap and refrigerate for at least 2 hours.
Make the cream cheese frosting: In a large bowl, beat the cream cheese, butter, and vanilla extract on high speed until smooth, about 2 minutes. Beat in the powdered sugar until smooth, about another 2 minutes.
8 ounces cream cheese, ¾ cup unsalted butter, 1 tablespoon pure vanilla extract, 5 cups powdered sugar
Once the cakes have chilled, use a large serrated knife to cut the dome tops off both cakes so they both have a flat top.
Place a thin layer of frosting (about 2 tablespoons) in the middle of a cake board or cake plate then place one cake (cut side facing up) on top of that frosting.
Add a generous layer of frosting on top of that first layer of cake then place the second layer of cake (bottom facing up) on top of the first layer of cake.
Frost a thin layer of frosting around the top and sides of the cake to crumb coat. Use a tool like a cake scraper to smooth the icing out.
Place the lightly frosted cake in the freezer for 10 minutes so the first layer of frosting firms up a bit.
Remove cake from freezer and apply the second layer of frosting. Spread this layer as smoothly as you can using the cake scraper.
Take the remaining frosting and color it pink. Place 1 cup of pink frosting in an icing bag fitted with a small star tip and pipe a heart on the top of the cake in the middle. Then, pipe small stars around the bottom outer edge of the cake.
1-2 drops pink gel food coloring
With the remaining pink frosting, place it in an icing bag fitted with a small round tip and frost circles around the top of the cake. Don’t pipe the circles too close to the edge, or they may drip down the sides of the cake.
Place the cake back into the freezer for about 10 minutes just to firm up those icing details.