Preheat the oven to 350°F (175°C).
Grease a 9x13 inch baking dish.
In a mixing bowl, combine the cake mix and melted butter until crumbly.
Press half of the mixture into the bottom of the baking dish.
In another bowl, beat the cream cheese until smooth.
Add powdered sugar and vanilla extract to the cream cheese; mix well.
Spread the cream cheese mixture over the cake layer in the pan.
Layer the sliced strawberries over the cream cheese.
Top with the remaining cake mixture, spreading evenly.
Bake for 40-45 minutes or until golden brown.
Let it cool before topping with whipped cream and graham cracker crumbs.