Giant Reese's stuffed monster cookies are the most delicious & indulgent dessert! Cookies bigger than your hand that are loaded with oats, peanut butter, chocolate chips, mini m&m's. The best part is the Reese's peanut butter cup stuffed inside the thick , soft baked & chewy monster cookie.
In a large bowl (or bowl of a stand mixer) cream together the butter, peanut butter, and brown sugar until light and fluffy, about 3-4 minutes. Mix in the egg and vanilla, scraping down the sides of the bowl as needed.
In a separate bowl, add the flour, baking soda, cornstarch, baking powder, and salt and whisk to combine. Add the flour mixture to the wet ingredients and mix until just combined.
Bake the cookies for 12-14 minutes or until the edges are just starting to brown and the top still looks slightly undercooked. Remove from the oven and cool for 5 minutes on the baking sheet before moving them to a wire rack to cool completely.
If making smaller cookies then use the miniature Reese's peanut butter cups instead. Reduce cooking time by a few minutes.
I find the snack size Reese's in a 12-pack in the candy aisle of the store.
For a pretty presentation, press a few additional mini m&m's onto the tops of the cookie dough balls after you shape them.