Preheat the oven to 350 ℉. Line a baking sheet with parchment paper or a silicone baking mat and set aside.
In a medium bowl, whisk together the flour, baking soda, baking powder and salt.
Using a standing mixer, or hand held mixer with a large bowl, mix the cooled brown butter and granulated sugar until combined, about 1-2 minutes, scraping down the sides of the bowl as necessary.
Mix in the egg and vanilla extract until combined, scraping down sides of bowl with a spatula as needed.
Add flour, baking soda, baking powder, and salt. Mix until just combined, being sure not to overmix the cookie dough.
Drop 1-2 tablespoon balls of cookie dough onto the prepared baking sheet, keeping them 2-3 inches apart. If desired, roll the balls of cookie dough in extra granulated sugar prior to adding to the baking sheet.
Bake in the pre-heated oven for 9-12 minutes until the edges start to brown. Remove from oven and immediately tap the pan on the top of the oven. This will help the cookies settle down.
Then, let the cookies cool on the baking tray for a 5-10 minutes. Once they’ve started to firm up move the cookies to cooling rack to finish cooling. Once cool, enjoy!