Note: You can make these with Reese's miniature cups or Reese's Thins. I use the "snack size" which is quite large but it makes for an epic stuffed cookie. You can also make these "unstuffed" if you want a traditional crinkle cookie and you can get ~24 small cookies from this batch.
Mix the sugars, oil, and cocoa: In a large mixing bowl, whisk together the granulated sugar, dark brown sugar, and oil until well combined. Add the cocoa powder and whisk until the mixture is smooth and glossy.
1 cup granulated sugar, 1/2 cup packed dark brown sugar, 1/2 cup neutral oil, 3/4 cup unsweetened natural cocoa powder
Add the eggs: Add the eggs one at a time, whisking well after each addition. Whisk in the vanilla and espresso powder, if using. Continue whisking vigorously for 1-2 minutes Start Timer, until the mixture is smooth, shiny, and well combined.
3 large eggs, 1 tsp. instant espresso powder, 2 tsp. vanilla extract
Add the dry ingredients: In a separate bowl, whisk together the flour, baking powder, and salt.
2 cups all-purpose flour, 1½ tsp. baking powder, 1/2 tsp. fine salt
Combine ingredients: Add the dry ingredients to the chocolate mixture and fold together just until no flour streaks remain. The dough will be soft and sticky but resist the urge to add additional flour.
Chill the dough: Cover the cookie dough tightly and refrigerate for at least 2 hours Start Timer. For best results and easier handling, I like to chill the dough for closer to 6 hours, or overnight is fine!
Stuff with the Reese’s: Preheat the oven to 350°F and line baking sheets with parchment paper. Scoop about 2 Tbsp of cookie dough and gently flatten it into a small disc. Place a Reese’s Peanut Butter Cup in the center, then bring the dough up and around the candy to completely enclose it. You will probably need to add a little more cookie dough as needed, then gently roll into a ball. Repeat with the remaining dough and Reese’s. Dough may be sticky, so work quickly and keep dough refrigerated between batches.
Reese’s Peanut Butter Cups snack size
Coat the cookies: Place the granulated sugar in one shallow bowl and the powdered sugar in another. Roll each cookie dough ball first in the granulated sugar, followed by a very generous coating of powdered sugar. The cookies should be completely covered in a thick, snowy layer of powdered sugar. Don’t shake off the excess since this helps create those beautiful bright white tops and dramatic chocolate crinkles as the cookies bake.
1/3 cup granulated sugar, 1/2 cup powdered sugar
Bake: Arrange the cookies about 2 inches apart on the prepared baking sheets. Bake for ~10-12 minutes Start Timer, or until the tops are cracked and the edges are set, but the centers still look soft and slightly underbaked. Be careful not to overbake.
Cool: Allow the cookies to cool on the baking sheet for 5-10 minutes before transferring to a wire rack Start Timer. Enjoy slightly warm for an extra gooey peanut butter cup center!