01 -
Preheat oven to 175°C. Line a baking sheet with parchment paper and set aside.
02 -
Using a stand mixer or hand mixer, beat softened butter, brown sugar, and granulated sugar together until mixture is light and fluffy.
03 -
Add the egg, egg yolk, and vanilla extract to the creamed butter mixture. Mix until thoroughly combined, scraping the bowl as needed.
04 -
In a separate mixing bowl, whisk together flour, baking soda, baking powder, and salt.
05 -
Gradually add the dry ingredients to the wet ingredients, mixing on low until just combined. Do not overmix.
06 -
With a spatula or wooden spoon, fold in 170 grams of M&M's and chocolate chips until evenly distributed throughout the dough.
07 -
Using a medium cookie scoop, shape dough into balls and place them on the prepared baking tray, spacing 2-3 cm apart. Press remaining M&M's into the top of each dough ball.
08 -
Bake for 10 to 12 minutes or until cookies are lightly golden around the edges but still soft in the center.
09 -
Remove baking tray from oven and let cookies cool on a wire rack for 5 minutes before serving or storing.