0 Preheat oven to 375 degrees Fahrenheit.
1 Combine room-temperature butter, granulated sugar, light brown sugar, and vanilla in a large mixing bowl. Cream together with an electric mixer or stand mixer.
2 Stir eggs into creamed butter and sugar mixture.
3 Combine the flour, baking soda, and salt in a medium bowl.
4 Add dry ingredients to wet ingredients. Mix by hand, or with an electric mixer.
5 Separate the dough into three equal sections and place in bowls. Add red food coloring to one bowl and blue food coloring to the other bowl. Mix the dough until it reaches the desired shades of red and blue.
6 Combine the original cookie dough with the red dough and blue dough.
7 Mix in mini chocolate chips and M&M's.
8 Scoop out 1" dough balls using a cookie scoop or by hand with a spoon.
9 Place dough balls on a cookie sheet lined with parchment paper or a silicone baking mat. Gently press each ball down using your fingers and add additional M&M's on top if desired.
10 Bake at 375 degrees for 9-11 minutes until the edges are golden brown.
