1. Preheat oven to 350°F. Line a baking sheet with a silicone mat or parchment paper and set aside.
2. In a stand mixer, mix the butter, sugar and oil for about 1 minute on medium speed. Add the cocoa and vanilla and mix together. Then add in the egg and mix until combined.
3. Add the flour and baking powder and mix with a wooden spoon/spatula until smooth. Fold in the chocolate chips and the M&M’s (save a few to add on top).
4. Using a cookie scoop, scoop out the dough and place onto the baking pan. Press a few M&M’s on top of each cookie to make them pretty. Bake for 10-12 minutes, or until the edges are lightly crisp and the middles are still soft.
5. Allow cookies to cool on the pan for a few minutes and then transfer to a cooling rack.