Preheat oven to 375º F. Line baking sheet with parchment paper and set aside.
In a medium bowl, whisk together flour, baking soda and salt. Set aside.
In the bowl of a stand mixer (or using a hand mixer and a large bowl), combine 1/2 cup granulated sugar, brown sugar, butter, and peanut butter. Beat until combined and fluffy, about 2 minutes. Scrape down the sides when necessary. Add egg and vanilla. Beating until mixed, about 30 seconds.
With the mixer on low, slowly add the flour mixture and beat just until combined.
Scoop a full tablespoon of dough and roll into 1 inch balls. Roll the cookie dough ball in the extra sugar and place on baking sheet. Place balls 1 1/2 inches apart.
Bake for 10 minutes, or until light golden brown, then remove from oven and allow to cool for only 3 minutes before pressing mini Reese's cup into the center. Immediately transfer to a wire rack to cool.
Melt chocolate chips in microwave at 50% power levels topping to stir every 15 seconds until melted. Transfer to a plastic baggie, snip the corner and pipe melted chocolate on the cookies to make spider legs. Place a dab of chocolate on the back of the candy eyes and press them onto the Reese's cup. Allow chocolate to set before serving.
Notes
Peanut butter: Use creamy no-stir peanut butter for this recipe. I use Skippy all natural peanut butter.Candy eyes: You can find these at your local grocery store or craft store.Climate: If baking in a warm climate, I suggest chilling the cookie dough for 30 minutes before baking. This will help prevent the cookies from spreading.Store cookies in an airtight container at room temperature for up to 5 days.Freeze cookie dough for up to 3 months.