12tablespoonsunsalted butter, melted and cooled slightly
1cuplight or dark brown sugar( 7 ounces)
½cupgranulated sugar(3½ ounces)
1large egg
1large egg yolk
2teaspoonsvanilla extract
1-2cupscandy covered chocolate pieces,of course you know 2 cups is best!
Instructions
Heat oven to 325 degrees with racks in the upper-middle and lower-middle positions.
In a medium bowl mix flour, salt, and baking soda. Set aside.
With electric mixer, beat butter and sugars until thoroughly blended. Mix in egg, egg yolk, and vanilla. Add dry ingredients and mix just until combined. Stir in M&M's.
Roll a scant ¼ cup of dough into a ball. Holding the ball in both hands, pull ball apart into 2 equal halves. Rotate just 90 degrees so jagged edges face up and press the two pieces back together again. Place on baking sheet with jagged edges facing up, spacing 2½ inches apart.
Bake 15-18 minutes. Cookies should be slightly undercooked when you remove them from the oven. Cool cookies on baking sheets.
Notes
Cookies can be stored in an airtight container at room temperature for 5 days.