Preheat oven to 350°F. Line two cookie sheets with parchment paper or silicone baking mats.

Cream butter, peanut butter, and brown sugar with a mixer until smooth. Mix in vanilla, egg, and milk. Add pudding mix and baking soda; mix well. Slowly add flour, then fold in chocolate chips and sprinkles.

Using a 2-tablespoon cookie scoop, form dough into balls and place on prepared baking sheets. Flatten slightly with a fork in a criss-cross pattern. Top with extra chocolate chips or sprinkles if desired.

Bake for 8-12 minutes until cookies are just set. Remove from oven, press candy eyes on top if using. Cool on baking sheets for 5 minutes, then transfer to wire racks to cool completely.