Preheat oven to 350F.
In a large glass bowl, melt butter by running for 10-15 seconds then pausing microwave for 10 seconds. Do this a few times until it is melted (or at least totally softened).
With a hand mixer, mixer butter and sugars together.
Add peanut butter and corn syrup.
Add eggs and vanilla and mix until just combined.
With a spatula or wooden spoon, mix in salt, baking soda, and quick oats.
Finally, mix in M&M and chocolate chips.
Using a cookie scoop - scoop 12 dough balls onto a cookie sheet lined with parchment.
Bake 12-15 minutes until they begin to turn golden brown. Remove from the oven and let sit until fully cooled (about 10-15 minutes).
