Preheat the Oven: Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans or line them with parchment paper.
Prepare the Cake Batter: In a large bowl, combine the cake mix and strawberry gelatin. Add the eggs, vegetable oil, pureed strawberries, and water. Use an electric mixer to beat the mixture on medium speed until smooth, about 2 minutes.
Bake the Cakes: Divide the batter evenly between the prepared cake pans. Bake for 25–30 minutes, or until a toothpick inserted into the center comes out clean.
Cool the Cakes: Let the cakes cool in the pans for 10 minutes, then transfer them to a wire rack to cool completely.
Make the Frosting: In a mixing bowl, beat the cream cheese and butter together until smooth. Gradually add the powdered sugar, 1 cup at a time, while mixing on low speed. Stir in the strawberry puree and vanilla extract, then beat until the frosting is creamy and well combined.