• Preheat the oven to 350℉ and line a large baking sheet with parchment paper.

Make the Brown Butter

• Heat a large skillet over medium-low heat. Add the butter, distributing it around the pan with a baking spatula as it melts.
• Once the butter has melted, keep a close eye on it, stirring occasionally. The butter will simmer and become very foamy before it starts to turn a golden brown colour.
• When the foam has cleared and the butter is a deep golden brown colour with a rich and fragrant caramel scent, it is ready. Remove the browned butter from the heat to avoid burning. This process will take about 10 minutes.
• Fill a large mixing bowl with cold water and ice cubes. Transfer the brown butter into a smaller mixing bowl, which fits inside this large one. Place the bowl with the brown butter inside the ice bath bowl. Using a whisk, whip the brown butter until it begins to solidify and form peaks, about 5 minutes.

Prepare the Cookie Dough

• To the bowl with the brown butter, add the white and brown sugars. Using a baking spatula, incorporate the sugars into the butter. Fold in the egg, then add the molasses and vanilla extract and mix once more until combined.
• Drain the ice bath bowl and pat it dry with a clean towel. Sift the oat flour, tapioca starch, baking soda, spices, and salt into the dry bowl. Whisk until combined.
• Pour the dry ingredients into the brown butter bowl and mix until just combined.
• Use a medium cookie scoop (~1½ tablespoons) to scoop the dough onto the lined baking sheet.
• Pour some white sugar onto a plate, then roll the balls of cookie dough in the sugar to coat.
• Transfer the cookie sheet to the freezer and chill the dough for 10 minutes before baking.

Bake the Cookies

• Bake the cookies, leaving two inches between each, for 10 minutes, rotating the pan after 5 minutes. I can fit 8 cookies on a large baking sheet. Allow the cookies to cool for 5 minutes on the pan before transferring to a wire rack to cool completely.