Preheat the oven to 350°F. Line a baking sheet with parchment paper and set aside.
In the bowl of a stand mixer fitted with a paddle attachment cream the butter, brown sugar and granulated sugar on medium speed for 1-2 minutes. Add the eggs, peanut butter, and vanilla extract and mix for another minute until combined.
Scrape down the sides of the bowl with a rubber spatula.
Add oats, baking soda, and salt and mix until partially combined. Add the mini M&M’s, chocolate chips, and mini chocolate chips and mix to combine.
Portion the dough into 3 tablespoon sized balls. Place the cookie dough balls on the baking sheet, leaving 2 inches between each ball. Using the palm of your hand press down on the tops of the cookie dough balls until they become a thick disk.
Bake for 11-13 minutes or until the edges are set and lightly golden.
Remove from the oven and let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.