To me, one of the coolest things about baking cookies from scratch is that once you have a basic cookie recipe, you can customize every batch you make by tweaking it. I love chocolate cookies, and I'm crazy about the crunchiness of m&ms baked into regular cookies. So when my friend had his birthday last week, I decided to take the chocolate and the crunch and combine them, using reese's pieces for a peanut buttery twist.

*makes about 18 cookies

1/2 cup butter
3/4 cup granulated sugar
1/4 cup brown sugar
1 tsp vanilla extract
1 egg yolk
2 tbsp milk
1+1/4 cup all purpose flour
1/4 cup cocoa powder
1/2 tsp baking soda
1/2 tsp salt
1/2 cup semisweet chocolate chips
1/2 cup reese's pieces

Melt the butter in a microwave or a double boiler. Add the granulated and brown sugar and stir until slushy. Stir in the vanilla, egg yolk, and milk. Combine flour, cocoa powder, baking soda, and salt in a separate bowl before adding them to the liquid ingredients. Incorporate the chocolate chips but leave out the reese's pieces. Chill the dough for an hour before baking.

Preheat the oven to 375 degrees F. Drop round teaspoonfuls of dough onto an ungreased cookie sheet. Arrange reese's pieces on top of each dough ball. Bake at 375 degrees F for about 8-10 minutes, until the cookies are crisp on the outside.