Step 1

Preheat the oven to 350° and grease a 9×13 pan.

Step 2

Mix the cake mix, butter, and egg in a large bowl with electric mixer on medium speed until blended and crumbly.

Step 3

Stir in 1 1/2 cups chocolate chips and nuts with a wooden spoon.

Step 4

Set aside 1 1/2 cups of the crumb mixture. Firmly press the remaining crumb mixture into prepared pan.

Step 5

Bake 15 minutes.

Step 6

Pour the condensed milk evenly over partially baked crust. Sprinkle with 1 cup of the toffee bits. Sprinkle with the reserved crumb mixture and remaining 1/2 cup chocolate chips.

Step 7

Bake 25 to 28 minutes or until golden brown.

Step 8

Immediately sprinkle with the remaining 1/4 cup toffee bits.

Step 9

Transfer to wire rack and cool completely. Cut into bars.