Step 1
Preheat the oven to 350 degrees F (175 degrees C). Line three 9-inch round cake pans with parchment paper.
Step 2
Beat cake mix water eggs and oil in a bowl with an electric mixer on medium speed for 2 minutes. Pour 1/3 of the batter into one of the prepared pans. Mix 1/2 of the strawberry-flavored gelatin and 2 teaspoons strawberry extract into the remaining batter. Divide between the remaining 2 pans.
Step 3
Bake cakes in the preheated oven until a toothpick inserted into the center comes out clean 15 to 20 minutes. Line a large wire rack with parchment paper. Invert cakes onto the rack; let cool completely.
Step 4
Set aside 9 to 12 whole strawberries for decoration. Chop remaining strawberries and pat dry with a paper towel.
Step 5
Beat cream cheese with the remaining strawberry-flavored gelatin. Add remaining 2 teaspoons strawberry extract and confectioners' sugar; beat until filling is smooth. Fold in chopped strawberries.
Step 6
Place 1 pink layer on a cake plate. Cover with 1/2 of the strawberry filling. Add the plain cake layer. Cover with remaining strawberry filling and position second pink layer on top.
Step 7
Make frosting by beating heavy cream confectioners' sugar and vanilla extract together until dense enough to spread. Spread frosting over the top and sides of the cake. Place a piece of parchment paper on top of the cake. Run spatula over the paper to smooth the top. Peel off the paper.
Step 8
Pipe 9 to 12 swirls of frosting around the rim of the cake; place whole strawberries on top.