Bake the cake in a 9x13 cake pan according to the box directions.
1 white cake mix
While the cake is baking, prepare your fresh strawberry sauce. Combine strawberries, sugar and lemon juice in a medium sauce pan. Cook until the mixture thickens, about six minutes. (If using frozen strawberries, it will take a little longer). Once the sauce coats the back of a wooden spoon, pour it into a large bowl and set aside.
1 cup fresh strawberries, 1 tbsp fresh lemon juice, 1/2 cup granulated sugar
Once the cake finishes baking, take it out of the oven and let it cool for about 15 minutes. Once cool, use the end of a wooden spoon to poke holes in the cake.
Prepare the Jello mixture (3 oz package) with boiling water, using the directions on the back of the box. Pour Jello over the top of your cake, filling in the holes. Spread the strawberry sauce over the top and let cool completely.
1 box strawberry Jello
Top the cake by spreading Cool Whip evenly across the entire cake.
10 oz Cool Whip
Garnish with sliced strawberries and chill for at least three hours. Serve cold and enjoy.
1 pint fresh strawberries
Serve cold and enjoy.
Notes
If you don't have white cake mix, you can use yellow instead. For extra strawberry flavor, try this recipe with strawberry cake mix.
Feel free to substitute homemade whipped cream if you prefer it to Cool Whip.