- Whip the butter at room temperature with brown sugar for 2-3 minutes.
- Add the egg, vanilla extract, and whip again.
- Sift the dry ingredients (flour, cocoa, baking soda and salt), and add to the previously whipped mass.
- Mix well. Roll into balls, insert m&m's and heat-resistant chocolate drops in a circle. * I got 10 cookies.
- Put the cookies on a baking sheet covered with parchment paper at a great distance from each other, because they diverge well.
- Bake for 9-11 minutes at 338F (170C). Focus on your oven.
- The finished cookies will be soft. Let them cool on the baking sheet for 10 minutes, then transfer to the wire rack.