Ingredients
Scale
- 1/3 cup 6 tablespoons unsalted butter, softened
- ¾ cup light brown sugar
- 1 teaspoon vanilla extract
- 3/4 cup creamy peanut butter (divided)
- 1 large egg
- ½ cup old-fashioned rolled oats
- ¾ cup all-purpose flour
- ½ teaspoon baking powder
- ½ teaspoon baking soda
- ¼ teaspoon salt
- ½ cup chocolate chips
- ½ cup M&Ms (I used peanut)
Instructions
- Grease a 6-inch or 8-inch cast iron skillet with butter. Set aside.
- In a large bowl, cream together butter and brown sugar until light and fluffy. Beat in 1/4 cup peanut butter and vanilla extract. Whisk in the egg until well blended.
- Stir in the oats, flour, baking powder, baking soda, and salt.
- Fold in chocolate chips and M&Ms. Chill cookie dough, covered, at least 2 hours and up to 3 days.
- Press about ⅓ of the dough into the bottom of prepared skillet (the entire bottom and sides of the skillet should be covered with dough). Fill with 1/2 cup peanut butter. Top with more dough until the top is completely covered and the peanut butter is sealed inside. Garnish with extra chocolate chips and M&Ms if desired. Cover with foil and refrigerate for at least 30 minutes, or up to 3 days.
- When you’re ready to bake, preheat oven to 350ºF.
- Bake for 25-30 minutes or until golden brown on top. Serve immediately with ice cream.