Preheat oven to 350°F. Line 2 cookie sheets with parchment or silpat baking mats. Place 1/4 cup granulated sugar in a bowl and set aside.

Cream butter, peanut butter, and brown sugar, and 1/4 cup granulated sugar in the bowl of an electric mixer fitted with the paddle attachment. Add egg, vanilla, milk, and salt and baking soda. Mix until combined. Slowly add flour and mix until dough comes together.

Scoop 1 tablespoon sized balls of dough and roll them in the bowl of sugar. Place on cookie sheets. Bake for 7-8 minutes, until the bottoms just begin to look brown. Remove from oven and immediately press a hole in the center of each cookie with the back of a wooden spoon. Insert a mini marshmallow in the hole and place back in the oven for 30 seconds. Remove from oven and stick a Reese’s Mini on top of the marshmallow, pressing gently to fit it into the hole without cracking the cookie. Cool completely before removing from cookie sheets.

Store in an airtight container for up to 3 days. They can be frozen in sealable containers or ziploc bags between layers of paper towels for up to one month.