01 -
Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking pan or line it with parchment paper for easy removal.
02 -
In a large bowl, combine the yellow cake mix, melted butter, and egg. Mix until well combined and crumbly.
03 -
Press about two-thirds of the mixture evenly into the bottom of the prepared baking pan to form the crust.
04 -
Pour the sweetened condensed milk evenly over the crust, spreading gently to cover.
05 -
Sprinkle the chocolate chips and toffee bits evenly over the condensed milk layer.
06 -
Crumble the remaining cake mix mixture over the top.
07 -
Bake for 25–30 minutes, or until golden brown and set. The edges should be slightly crispy, but the center may still look a bit gooey.
08 -
Remove from the oven and allow to cool completely in the pan. Slice into bars and enjoy!