Peanut Butter Cup Monster Cookie Recipe

Preheat oven to 350 degrees F (177 degrees C). Line 2 large baking sheets with parchment paper or silicone baking mats. Set aside.

Toss the flour, salt, and baking soda together in a large bowl. Set aside.

In a medium bowl, whisk the melted butter and brown sugar together until no brown sugar lumps remain. Whisk in the egg, then the peanut butter until combined.

Finally, whisk in the vanilla. Pour the wet ingredients into the dry ingredients and mix together with a large spoon or rubber spatula.

The dough will be very soft and slick. Fold in the oats and the M&Ms. Allow the cookie dough to sit for 15 minutes.

Take 1 Tablespoon of dough and slightly flatten out on the prepared baking sheet. Stick a peanut butter cup on top, as shown above.

Top the peanut butter cup with 1½ Tablespoons of cookie dough and seal down the sides so that the peanut butter cup is securely stuffed inside.

Slightly flatten down the top. Repeat with the rest of the dough and peanut butter cups.

Bake the cookies for 12 to 13 minutes. The cookies will look very soft. They will continue to bake on the cookie sheet.

Remove from the oven and lightly press down on each cookie to slightly flatten. 

Allow to cool on the cookie sheet for 10 minutes before transferring to a wire rack to cool completely.