01 -
Preheat your oven to 350°F and line a baking sheet with parchment paper to prevent sticking.
02 -
In a large mixing bowl, beat softened butter, smooth peanut butter, brown sugar, and granulated sugar until light and fluffy. Add egg and vanilla extract, mixing until fully incorporated.
03 -
Whisk all-purpose flour, baking powder, baking soda, cornstarch, and salt in a separate bowl. Gradually add to wet ingredients, stirring gently until no flour streaks remain; avoid overmixing.
04 -
Divide dough into nine equal balls using a large scoop. Roll between palms, flatten to about 1 inch thick discs, arrange on baking sheet, and freeze for 15 minutes to maintain shape during baking.
05 -
Bake chilled discs in the preheated oven for 12 to 13 minutes until edges are set and lightly golden. Allow to cool on the pan for 10 minutes; centers will firm as they cool.
06 -
Melt milk chocolate chips with vegetable oil in a microwave-safe bowl using 30-second intervals, stirring between each until smooth and pourable.
07 -
While cookies are warm, spread melted chocolate evenly on each. Immediately top with three muddy buddies per cookie. Let cool completely to set chocolate before serving.