Preheat oven to 375°F (190°C).
In a bowl, cream together the butter, sugars, egg, and vanilla until smooth.
Add flour, baking soda, baking powder, and salt, mixing until a dough forms.
Fold in the M&M candies. Do not overmix.
Scoop cookie dough onto a baking sheet lined with parchment paper. I wweigh each cookie to 100 to 120 grams. makes giant cookies . Add extra M&M’s on top for a festive look.
Chill for at least 30 minutes.
Bake for 15 minutes, until edges are golden but centers remain soft.
Let cool on the tray for 5 minutes before transferring to a wire rack.