Preheat oven to 350º F. Cream butter then add sugars and mix until light and fluffy. Add eggs and vanilla and mix until well-combined. Add flour, cocoa powder, salt and baking soda to butter mixture. Mix well and then stir in toffee bits.
Scoop cookie dough onto a cookie sheet spacing well apart to allow room for the cookie to spread lightly.
Bake for about 10-12 minutes or until lightly browned.