Heat butter in small skillet on medium heat. Allow to froth up, then brown. Here is a great article on how to brown butter (for today's cookies you want the butter to JUST begin the browning process) Remove from heat.
In large mixing bowl, add browned butter and 1 ¾ cups brown sugar. Mix on medium speed, add salt, eggs and vanilla. Stir in flour, baking soda and baking powder.
In small bowl, mix ¼ cup reserved brown sugar and 2 Tbsp granulated sugar together. Using a 1 Tbsp small scoop, scoop up dough (will be consistency of play-doh) and roll into a ball. Then roll in sugars. Place on cookie sheet with parchment paper. Bake in a 375 degree oven for 10 minutes.