1 15.25 ounce box yellow cake mix
1/2 cup melted butter
3 egg divided use
9 ounces cream cheese
2 teaspoons vanilla extract
5 cups powdered sugar divided use
Preheat the oven to 350°F and generously spray a jellyroll pan with nonstick spray.
To make the crust, using an electric mixer on low speed, blend the dry cake mix, melted butter, and 1 egg until moistened. Then increase the speed to medium for 2 minutes. Pat the mixture onto the bottom and sides of the jellyroll pan. Set aside.
To make the filling, mix the cream cheese, vanilla, 3 1/2 cups of powdered sugar, and the remaining 2 eggs until moistened. Cover the mixer with a large, clean kitchen towel and carefully increase the speed to high for 5 minutes. Return mixer to low speed and remove towel. Add the remaining 1 1/2 cups powdered sugar and mix until well blended. Replace the towel and return mixer to high speed for an additional 5 minutes.
Pour the filling evenly over the crust in the jellyroll pan and bake in the preheated oven for 40 minutes or until golden brown. When cool, slice into squares.