Pre-heat oven to 350 degrees. Line 2 baking sheets with parchment paper and set aside.

In a large mixer, combine the softened butter and brown sugar with a paddle attachment for 2 minutes.

Add the eggs one at a time, followed by the vanilla extract.

Add the flour, baking soda, sea salt and baking powder and slowly combine, making sure not to over-mix the batter.

Add the oats and M&M's and combine.

Refrigerate batter for 1 hour.

Using a 1 inch scoop, scoop 12 cookies onto each parchment lined baking sheet. Transfer sheets into over and bake for 10-12 minutes until the cookies just slightly turn a golden brown color on the edges but are still soft and chewy in the middle. Remove from oven, transfer to cooling rack. Repeat process for remaining dough.