Preheat the oven to 350℉. Line 2 sheet pans with parchment paper.

Combine the soft butter and sugar in a large bowl and stir until creamy and well combined. Add the egg yolks and vanilla and stir again.

Add the baking soda and baking powder and stir until incorporated then add the flour. Stir until all of the flour has been combined and the dough starts to clump.

Add the toffee bits and stir until incorporated and no loose bits are at the bottom of the bowl.

Scoop up the dough with a 1½-2 tablespoon ice cream scooper into mounds spaced 2 inches apart on the prepared sheet pans. Pack the dough into the scooper tightly.

Bake for 12-16 minutes or until lightly golden brown. Remove from the oven and sprinkle lightly with sugar, if desired. Allow to sit on the pan for 4-5 minutes, then transfer to a cooling rack to cool completely.