1Heat 10 tablespoons of the butter in a pan over medium-high heat until melted. Continue to cook the butter until it is browned a dark golden color and smells nutty, about 1 to 3 minutes.
Transfer the browned butter to a bowl and stir the rest of the butter into the hot butter until it melts- let this rest for 15 min.
2Mix 2 cups plus 2 tablespoons of flour, baking soda, and baking powder in a bowl.
Add the 1 and 3/4 cup brown sugar and salt to cooled butter and mix until there are no lumps. Add egg, yolk, and vanilla to butter mixture and mix well, then add flour and mix until just combined.
3Place the 1/4 cup red sugar crystals and the 1/4 cup green sugar crystals in separate dishes.
4Preheat oven to 350 degrees.
Roll dough into balls about 1 and 1/2 inches in diameter. Then roll one dozen in the red sugar crystals and one dozen in the green sugar crystals. Place balls about 2-inches apart on parchment lined baking sheets.
5Bake sheets one at a time until cookies are puffy and lightly browned, about 12- 14 minutes. (The cookies will look slightly raw between some of the cracks and seem underdone, but be careful not to over bake.)
Cool on sheet for about 5 minutes and then transfer to a rack to cool.