Step 1: Preheat your oven to 350°F (175°C) and line two large baking sheets with parchment paper for your sinister spider cookies recipe.
Step 2: In a large bowl, cream together the butter, peanut butter, granulated sugar, and brown sugar until smooth and fluffy.
Step 3: Beat in the egg and vanilla extract until well combined.
Step 4: In a separate bowl, whisk together the flour, baking soda, and baking powder. Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Step 5: Shape the dough into 1-inch balls and place them 2 inches apart on the prepared baking sheets.
Step 6: Bake for 8 to 10 minutes, or until the edges are lightly golden. The centers of your sinister spider cookies recipe should still look soft.
Step 7: Immediately after removing from the oven, press a miniature peanut butter cup upside down into the center of each cookie. Allow the cookies to cool completely before adding the legs.
Step 8: Melt the chocolate chips in the microwave in 30-second intervals until smooth. Transfer to a piping bag with a small round tip.
Step 9: Pipe four legs on each side of the peanut butter cup, starting from the cup and moving toward the edge of the cookie.
Step 10: Use a small dot of melted chocolate to attach two candy eyeballs to the front of each peanut butter cup to complete your sinister spider cookies recipe.