• Brown butter according to the instructions in my How to Make Brown Butter post (do not add any water to butter after it's browned); set aside a few hours to cool completely to room temperature. When it's ready, your browned butter should be soft, but cool to the touch.
• To make the cookies, preheat oven to 375°F and line a large baking sheet with parchment paper or a silicone baking liner.
• In a large bowl, mix solidified brown butter on medium speed with an electric mixer. Add brown sugar gradually, and cream together for 3 minutes, scraping sides of bowl as needed.
  1 cup light brown sugar, 1¼ cup unsalted butter
• Mix in egg, followed by vanilla, until smooth.
  1 large egg, 2 teaspoon pure vanilla extract
• In a separate bowl, whisk together flour, cornstarch, baking powder, and salt.
  3½ cups all-purpose flour, 1 tablespoon cornstarch, 2 teaspoon baking powder, ½ teaspoon salt
• While mixing on low speed, add dry ingredients to wet ingredients slowly, until just barely combined. Dough will be very thick, and you will likely need to help bring it together by hand.
• Turn dough out onto a floured surface and, with floured hands, form into a ball.
• Dust rolling pin with flour and roll dough out to approximately ¼-inch thick.
• Coat cookie cutters with flour and cut dough into shapes.
• Use a bench scraper to transfer cut cookie dough to prepared baking sheet. Bake for 7-9 minutes in preheated oven.
• Remove from oven and let sit on baking sheet for 10 minutes; then transfer to a cooling rack to cool completely.

Easy Vanilla Icing

• In a bowl, whisk together powdered sugar, brown sugar, vanilla, milk, and salt. Add additional milk if needed for desired consistency.
  2 cups powdered sugar, ½ cup brown sugar, 3 teaspoon milk, ½ teaspoon pure vanilla extract, pinch salt
• To dip icing: one at a time, hold a cooled cookie upside-down by the outside edges and dip face-down into the icing. Be sure that the whole surface of the cookie is in contact with the icing.
• Lift cookie up and allow excess to drip from the surface of the cookie back into the bowl for about 15-20 seconds.
• Carefully flip cookie, without allowing any dripping icing to spill onto the sides, and place on parchment or cooling rack.
• To spread icing: Spoon a small spoonful of icing in the center of each cookies and spread carefully around close to the edges of the cookie shape. Place on cooling rack to set before serving.