Step 1

Preheat oven to 350 degrees and line two rimmed baking sheets with parchment paper.  Set aside.

Step 2

Place butter in a medium skillet (preferably not nonstick or cast iron so that you can more easily see the color change) and heat over medium low heat, swirling the pan frequently.  Once the butter has melted, continue to cook, swirling the pan frequently, until the butter has a nutty aroma and is golden brown in color.  Don’t walk away from the stove! Brown butter can go from perfect to burnt in a matter of seconds. Immediately transfer brown butter to a bowl to cool.

Step 3

Whisk oats, flour, baking powder and salt together in a medium bowl.  Set aside.

Step 4

Combine egg, sugar and vanilla in a large bowl and whisk until sugar is dissoved and mixture is frothy.  Add brown butter and whisk until everything has just come together. Add dry mixture and stir to combine.  Let the dough rest at room temperature for 10 minutes prior to making the cookies.

Step 5

Drop heaping teaspoonfuls of batter onto prepared cookie sheet, leaving at least 2 inches between each cookie (they will spread considerably).  Bake 10-12 minutes, or until the cookies are set and the edges are golden brown. Cool for a few minutes on the baking sheet and then transfer to a wire rack to cool completely.  Repeat with remaining batter.