(In parentheses for 12″ skillet)
3/4 c. plus 1/4 c. (1 1/4 c. plus 1/2 c.) creamy peanut butter
1/2 c. (3/4 c.) butter
1/2 c. (3/4 c.) brown sugar packed
1/4 c. (1/3 c.) granulated sugar
1 large egg (2 egg)
1 tsp. (1/2 tbsp.) pure vanilla extract
1 1/2 c. (2 1/4 c.) all-purpose flour
1/2 tsp. (3/4 tsp.) baking soda
1/2 tsp. (3/4 tsp.) kosher salt
13 (18.72) Reese’s Cups
1 1/2 c. (a lot) mini Reese’s Cups, plus more for topping
1/4 c. (a lot) Reese’s Pieces, plus more for topping
Melted chocolate for topping
Ice cream for topping
Preheat oven to 350°F and grease a 10-inch cast-iron skillet with cooking spray. In a large bowl using a hand mixer or in the bowl of a stand mixer, combine ½ cup peanut butter, butter, and sugars and beat on medium until mixture is light and fluffy. Add egg and vanilla and mix until thoroughly combined, then add flour, baking soda, and salt and mix until just combined.
Press half the cookie dough onto the bottom and up the sides of the skillet. Press Reese’s Cups into dough, then top with remaining cookie dough. Gently press in 1½ cups mini Reese’s Cups and ¼ cup Reese’s Pieces.
Bake until cookie is set, 15 to 20 minutes.
In a small microwave-safe bowl, microwave remaining ¼ cup peanut butter until melty, 20 seconds.
Drizzle cookie with melted peanut butter and melted chocolate, and top with more candy. Serve with ice cream.