01 -
Preheat oven to 350 degrees Fahrenheit. Line a baking sheet with parchment paper or a silicone baking mat and set aside.
02 -
In a mixing bowl, use a hand-held mixer to beat together the butter and sugar until light and fluffy.
03 -
Add the egg yolks and vanilla extract to the mixture. Beat until combined.
04 -
Gently mix the flour into the butter mixture until just combined. Avoid over-mixing.
05 -
Portion the dough into one-teaspoon-sized balls. Roll each ball in the sanding sugar and place on the prepared baking sheet. Press a chocolate M&M candy into the center of each ball.
06 -
Bake in the preheated oven for 10 minutes. Remove from oven and allow the cookies to cool on the baking sheet for 3-5 minutes before transferring to a wire cooling rack to cool completely.