Preheat oven to 350 degrees F and prepare a sheet pan with parchment paper 

In a medium bowl, combine the flour, baking soda and salt; set aside 

In a small microwave safe bowl, melt the butter to be almost fully melted but not hot 

In a mixing bowl with paddle attachment, combine the melted butter, light brown sugar, granulated sugar and vanilla extract; mix until combined and creamy

Add the egg to the butter mixture and mix until fully combined 

Slowly add the dry ingredients into the butter and sugar mixture and beat on medium speed until smooth

With the mixer on low speed, add in the chocolate chips and mini M&M’s 

Using a 1 tablespoon scoop or spoon, scoop the batter into a ball and place on the prepared sheet pan about 3 inches apart.  

Place the sheet pan in the preheated oven for 6-7 minutes (cookies will still be very light in color...do not over bake)

Remove the cookies from the oven and allow them to cool completely 

Store in an airtight container for 3-4 days or freeze if you are not enjoying immediately