A classic rendition of chewy Monster Cookies packed with the richness of peanut butter, wholesome oats, semisweet chocolate chips, and colorful M&M's. Perfectly soft with a slight crisp on the edge, these cookies are a guaranteed favorite among peanut butter lovers.
Cream together the unsalted butter, brown sugar, and granulated sugar in a large mixing bowl for about 4 minutes until the mixture is fluffy and pale. Blend in the peanut butter, egg, and vanilla extract, continuing to beat for an additional minute.
Incorporate the rolled oats, flour, baking soda, and salt, folding until the dough is just combined. Mix in the chocolate chips along with 3/4 cup of the M&M's, keeping the remaining 1/4 cup aside.
Cover the bowl and refrigerate the dough for 30 minutes.
Preheat your oven to 365°F. Once chilled, portion the dough onto a light-colored baking sheet, allowing at least two inches between each scoop.
Bake for 9 to 10 minutes. Upon removal from the oven, immediately press the reserved 1/4 cup of M&M's gently into the tops of the cookies. Allow the cookies to rest for 5 to 10 minutes on the baking sheet before transferring.
Notes
Variations: Consider adding butterscotch chips, peanut butter chips, salted caramel chips, or bits of salty pretzels for a unique twist.