Add the browned butter, brown sugar, granulated sugar, eggs, and vanilla extract to a mixing bowl. Whisk the ingredients together until fully combined.
With a hand mixer, mix the baking powder, baking soda, cinnamon, and salt (if using unsalted butter) into the wet ingredients. Gradually add the flour as you mix the dough. Use a spatula to scrape the sides of the bowl to ensure all the ingredients are fully combined.
Use a 2-tablespoon cookie scoop (or your hands) to scoop the dough onto a parchment paper-lined baking sheet. Chill the cookie dough in the fridge for 30 minutes. Preheat the oven to 350 degrees Fahrenheit.
Once the dough balls have chilled, roll them into round balls with your hand. Then roll them in a bowl of sprinkles (if adding sprinkles).
Place six balls of cookie dough on the baking sheet, separating them about 2 to 3 inches apart. Bake in the oven for 11 minutes or until the edges are slightly golden brown and the center is still soft and a little uncooked. They will cook more on the hot baking sheet.
Allow them to cool on the baking sheet for 10 minutes before transferring them to a wire cooling rack. Enjoy!