Preheat the oven to 350°F. Line an 8x8 inch baking dish with parchment paper and set aside.
Place the rolled oats in the bowl of a food processor and pulse until they are coarsely ground.
Add the egg, peanut butter, honey, baking soda, salt and vanilla and process until well combined and the dough comes together into a ball. Stir in the mini M&M’s.
Press the dough into the prepared baking dish. Bake for 22-24 minutes until lightly browned and a toothpick inserted in the center comes out cleanly. Let cool completely before slicing into bars.
These bars are best made with regular peanut butter. I have tried them with natural peanut butter too, and while still okay, they were quite dry. With regular peanut butter they were moist and chewy which we definitely preferred. Also, if you would like to cut the amount of M&M’s to just 1/4 cup, they were still delicious with this smaller amount.