In a large bowl, add the flour and baking soda and whisk together.

In another large bowl (or the bowl of your stand mixer), add the butter, shortening, and brown sugar and mix until fluffy (a few minutes).

Add in the eggs, beating well after each addition.

Add in the vanilla and beat.

Turn the mixer to low and scrape down the sides.

Gradually add in the flour mixture, mixing only until the flour disappears.

Cover bowl with plastic wrap and let chill in the fridge for at least an hour.

Once chilled, preheat your oven to 350 degrees and line baking sheets with parchment paper or silicone baking mats.

Use a medium cookie scoop to scoop out the dough and place 12 per baking sheet.

Press 4-5 M&Ms into the top of each dough ball.

Bake for 8-10 minutes or until just golden.

Remove from oven and immediately slide the parchment paper onto a cooling rack to cool completely.