We started our slice-and-bake mocha-peppermint cookie dough with melted rather than softened butter. This allowed us to skip the usual creaming step and simply stir in the sugar along with an egg yolk and peppermint extract.
A little baking powder opened up tiny air pockets in the dough and kept it from being too dense. The yolk’s proteins and the sugar gave the cookies a pleasantly firm and crumbly texture and extended their shelf life to 10 days, making them ideal for shipping or gifting.
