Chill the mini Reese’s Peanut Butter Cups in the freezer for about 20 minutes. Preheat your oven to 350°F (175°C).

In a large bowl, beat together ½ cup unsalted butter, ½ cup brown sugar, and ½ cup granulated sugar until light and fluffy. Add ¾ cup creamy peanut butter, 1 egg, and 1 teaspoon vanilla extract, and blend until smooth.

In a separate bowl, whisk together 1 ½ cups all-purpose flour, 1 teaspoon baking soda, ½ teaspoon baking powder, and ¼ teaspoon salt. Gradually mix it into the wet ingredients until just combined.

Scoop out dough, roll into balls, and roll in granulated sugar. Place on baking sheet, spaced 2 inches apart. Bake for 8-11 minutes until edges are golden and centers are set.

Remove cookies from the oven and press a chilled mini Reese’s Peanut Butter Cup into the center of each cookie. Cool on the baking sheet for a few minutes before transferring to a wire rack.

Melt ½ cup semi-sweet chocolate chips in a microwave-safe bowl, then use it to pipe spider legs from each Reese’s. Attach candy eyeballs using melted chocolate and let set before serving.