Vegetable oil cooking spray
1 (18.2- ounce) package yellow cake mix
1 large egg
1/2 cup (1 stick) butter, melted
1 (8-ounce) package cream cheese, softened
2 large eggs
1 teaspoon vanilla extract
1 (1 pound) box confectioners' sugar
1/2 cup (1 stick) butter, melted
1 cup toffee bits