In a large bowl, combine cake mix and gelatin. Add pureed strawberries, eggs, oil, and water, beat at medium speed with an electric mixer until smooth.

Pour into prepared pans and bake at 350 degrees for 20-25 minutes, or until wooden pick inserted in center comes out clean. Let cool in pans, and cool completely on wire racks.

For frosting, in a large bowl, beat butter and cream cheese at medium speed with an electric mixer until creamy. Beat in 1/4 cup strawberry puree, reserving for another use. Beat in extract. Gradually add confectioner's sugar, beating until smooth.

Spread Strawberry Cream Cheese Frosting in between layers and on top and sides of cake. Garnish with sliced fresh strawberries, if desired.