Browning the butter for the cookies and glaze

1. Slice the butter into chunks and melt in a skillet. I like to use my dutch oven since the bottom is cream-colored and I can tell when the butter is browned. Melt over medium heat, continuing to stir. The butter will start to foam, keep stirring for 6-8 minutes until little brown bits start to show up in the bottom of your pan. Once browned, remove from heat and set aside.

 Making the cookies

1. Preheat the oven to 350 °F and prepare a large baking sheet with parchment paper or Silpat.
2. In a large bowl whisk together rolled oats, all-purpose flour, baking soda, salt, pumpkin pie spice, and cinnamon.
3. Pour 1 cup of the browned butter into another large bowl. Add white and brown sugar to the bowl and whisk until combined. 
4. Add in the egg yolk and vanilla extract, and whisk again until combined. 
5. Add in the strained pumpkin puree and whisk. (See notes on straining pumpkin puree)
6. Add in the flour mixture half at a time, mix until combined. 
7. Use a medium or large cookie scoop, place cookie dough scoops on to your prepared baking sheets. Press down slightly on the cookie to preflatten.
8. Bake for 13-15 minutes or until lightly browned. Remove from the oven and allow to cool for at least 15 minutes before topping with the brown butter glaze.

To make the glaze

1. Use ¼ cup of the brown butter. If the brown butter is no longer liquid, warm slightly on the stove top or the microwave. Add in the powdered sugar, milk and vanilla, whisk to combine. Spread thinly on top of your cooled cookie, or dip the cookie into the glaze mixture.