Preheat oven to 350 degrees. Spray 9x13 baking dish with nonstick cooking spray.
Give your strawberries a good rinse then gently dry them with a paper towel. Remove the stems and dice them up. Then stick them in a plastic ziplock bag and start crushing them up using a rolling pin or something heavy. This will probably take you a minute or two.
In the bowl, combine cake mix with strawberry gelatin powder. Mix until combined. Then stir in oil, eggs and water. Once that is combined, add in 1 cup of the smashed strawberries. You will want to gently stir those in by hand.
Then pour batter into prepared baking dish. Bake for about 30-33 minutes. Stick a toothpick in center to check if it's done. Allow cake to cool completely before adding frosting.
To make frosting, mix together the softened butter and softened cream cheese.mix until smooth and creamy. Then add powdered sugar , vanilla extract and milk. Mix until creamy. Frost the cake and store in the frige.