Preheat oven to 325˚F. Line two sheet pans with parchment paper. Unwrap toffee bars and, with a sharp knife, cut them into bite size pieces. Set aside.

Place butter in a microwave-safe bowl (2 quart size is perfect. I use this one almost daily). Microwave on high power for 20-30 seconds or until butter is starting to melt and has become soft. Don’t let it melt completely, as the dough will be runny and the cookies will not have a good texture. (see picture in post)

Add sugars and mix with a wooden spoon or sturdy spatula until smooth and all brown sugar lumps are dissolved. Add vanilla and egg yolks, then stir again until smooth.

Add the flour and sprinkle the baking soda and salt over the top. Stir just until all flour mixture is incorporated and dough pulls away from sides of bowl. See “Tips” at the end of the post and picture in post.

Add ½ cup of the chocolate chips and half of the toffee bits. Stir to combine. Reserve remaining chocolate chips and toffee bits.

Scoop up dough with a spoon or an ice cream scooper of your choice and place on prepared sheet pan. Leave 1 ½-2 inches between each cookie. I like fairly large cookies and use a 2-inch ice cream scoop with a 3 tablespoon capacity.* Press a few of the reserved toffee pieces and chocolate chips onto the top and sides of each dough scoop for a pretty look. (If you’re in a hurry, just add all the chips and toffee pieces into the dough in step 5.)

Bake for 12-15 minutes or until cookies are light golden brown. Allow to cool for a few minutes on the pan, then transfer to a cooling rack.