Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan.

In a mixing bowl, combine the yellow cake mix, melted butter, and eggs. Mix until well combined.

Fold in the chocolate chips and toffee bits until evenly distributed.

Spread the mixture evenly into the prepared baking pan.

Bake in the preheated oven for 20-25 minutes, or until the edges are golden brown and a toothpick inserted in the center comes out clean.

Remove from the oven and allow to cool in the pan for 10 minutes before transferring to a wire rack to cool completely.

Once cooled, cut into bars and serve.