First, gather all your ingredients to make M&M Cookies.
Whisk the flour, baking soda, and salt in a medium bowl. Put this bowl aside for later.
In a mixing bowl, add the melted butter, white sugar and brown sugar. Whisk for 5 minutes on low or until well blended.
Next, Add 1 egg to the bowl and beat batter until egg is mixed through.
Crack the second egg into the bowl and add the vanilla extract. Beat well until all the ingredients are blended.
Add the dry bowl that was set aside earlier, slowly introduce the flour mixture into the wet batter. Beat the batter for 3-5 minutes on low to fully combine the ingredients.
Fold 1 cup of M&M minis into the batter. Be gentle and try not to break the shell of the M&M's. Cover the bowl and place in the refrigerator for 30-60 minutes.
Preheat oven to 375°F. Line a baking sheet with parchment paper or grease a pan. Remove from the fridge and start scooping your batter onto the parchment paper. I use a 1¼ inch cookie scoop to measure my batter. Place cookies 1 - 1½ inches apart. Use the ½ cup of M&M's to gently press into the tops of the batter balls.
Bake at 375°F for 8-10 minutes. Remove from oven and let cool on pan for 5 minutes. Transfer cookies to cooling rack and let stand for 5-10 minutes. Cookies will get slightly firmer over the next hour as they cool.