Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.
In a large bowl, cream the softened butter, granulated sugar, and brown sugar until light and fluffy, about 2 minutes.
1/2 cup butter, 1/3 cup white sugar, 1/2 cup brown sugar
Add the egg and vanilla extract and mix until combined.
1 large egg, 1 tsp vanilla extract
Add the flour, black cocoa powder, baking soda, and salt. Mix just until the flour disappears.
1 cup all-purpose flour, 2/3 cup Black cocoa powder, 1/4 tsp Salt, 1/2 tsp Baking soda
Fold in the Halloween sprinkles and peanut butter chips.
1/4 cup Halloween sprinkles, 3/4 cup peanut butter chips
Scoop 2 tablespoon dough balls onto the prepared baking sheet, spacing them 2 inches apart. Bake for 8 to 9 minutes.
Right out of the oven, press candy eyes and a few extra peanut butter chips into the tops. Let the cookies cool on the baking sheet for 15 minutes, then move them to a wire rack.
34 Halloween eye candies
Notes
Pull the cookies at 8 to 9 minutes even if the centers look soft. They set as they cool on the pan.
Black cocoa is what makes these black. Regular cocoa works but bakes up brown, so add black gel coloring if you swap.
Store airtight with a slice of bread for up to 5 days, or freeze up to 3 months.
Peanut-free: use white chocolate chips instead of peanut butter chips.