Preheat oven to 350 degrees F.
Line a baking sheet with parchment paper.
In a skillet, over medium heat melt ⅔ cup of butter, stir, and whisk it constantly. until it reaches a brownish color, about 3-4 minutes. Transfer it into a large bowl, and add the remaining butter, stir until melted in.
In another medium bowl whisk ½ cup brown sugar, flour, baking soda, baking powder, cinnamon, nutmeg, and salt.
Add remaining brown sugar to the melted butter and whisk it until smooth. Whisk in the egg, egg yolk, vanilla, and molasses.
Add the dry ingredients to the butter mixture and stir until a dough forms.
Roll dough out to ½-inch thick disk and use a cookie cutter to cut cookies, or roll into balls and place on a cookie sheet, slightly press them down and sprinkle on top with brown sugar and some cinnamon.
Bake for 12-14 minutes, or until cookies begin to set. Do not over-bake.
