adapted from Chew Out Loud
- 2¼ cups all purpose flour
- ½ tsp table salt
- ½ tsp baking soda
- 12 TB salted butter, melted
- 1 cup light brown sugar, packed
- ½ cup granulated sugar
- 1 large egg, room temp
- 1 large egg yolk, room temp
- 1 TB pure vanilla extract
- 1½ cups M&M's (holiday colors are great)
- Preheat oven to 325F with rack on lower middle position. Line a 9x13 baking pan with foil, with enough overhang on either side to make a sling (for ease of removal after baking.) Grease foil and set aside.
- In a bowl, whisk togehter the flour, salt, and baking soda.
- In another bowl, stir together the melted butter and both sugars. Stir in the egg and extra egg yolk. Stir in vanilla extract.
- Using a rubber spatula, fold together the dry mixture into the wet mixture, just until incorporated. Do no overmix. Fold in 1 cup of the M&M's. Reserve the rest for pressing on top.
- Using slightly wet fingers, press dough into an even layer in the greased and foiled pan, making sure to get an even thickness throughout. Press remaining M&M's on top of dough.
- Bake 25-28 minutes or just until it's puffy and golden brown. It may seem a bit underbaked, but go ahead and take it out. It will set nicely upon cooling.
- Let cool completely at room temp before removing with the foil sling. Remove entire dessert with the foil sling and place on a cutting board. Cut into squares. Leftovers will keep for days at room temp in an airtight container.