Preheat oven to 350 degrees F. Coat a 9×13 pan with cooking spray and set aside. In a medium bowl, combine cake mix, 1 egg and 1 stick of butter. Using a hand-held mixer, beat on medium speed until combined. Press into the bottom of the prepared pan and set aside.
Using a hand-held mixer, beat on medium speed until combined. Press into the bottom of the prepared pan and set aside.
Place the cream cheese, 2 eggs and the vanilla in a large bowl. Using a hand-held mixer, beat on medium speed until smooth. Add the powdered sugar and beat until smooth. Add 1 stick of butter and beat until smooth. Fold in the toffee bits using a spatula.
Pour mixture over top of the crust and spread evenly. Bake in the preheated oven for 40 to 45 minutes, leaving the center of the cake gooey. Add sprinkles, if desired. Let cool and cut into squares.
Notes
There is no chocolate in this recipe, but consider adding a half cup of mini chocolate chips.
Swap out the yellow cake mix with chocolate cake mix for a different flavor.
Add a dollop of whipped cream to the top of each piece just before serving and don't forget the sprinkles.