Blot the Pumpkin: Line a medium bowl with double‑layered paper towels. Place the pumpkin puree in the bowl, then press another paper towel over it to blot out excess moisture. Replace towels and repeat until about 1 cup (225 g) of thick pumpkin remains. Set aside.

Brown the Butter: In a light-colored skillet over medium heat, melt all of the butter (for both dough and glaze). Stir constantly. After 5–8 minutes, the butter will foam and then begin to brown (look for small browned bits and a nutty aroma). Immediately remove from heat, pour into a heat-safe bowl, scraping up the browned solids. Reserve a portion for the dough and the rest for glaze. Let it cool slightly.

Preheat & Prep: Preheat oven to 350 °F (177 °C). Line baking sheets with parchment paper or silicone mats.

Mix Dry Ingredients: In a large bowl, whisk oats, flour, baking soda, salt, cinnamon, and pumpkin pie spice until well combined.

Mix Wet Ingredients: In another bowl, whisk the reserved brown butter (for the dough), granulated sugar, and brown sugar until combined. Then whisk in the egg yolk, vanilla, and blotted pumpkin until smooth.

Combine: Gradually add the dry mixture into the wet mixture, stirring until just combined. The dough will be soft and slightly sticky.

Scoop & Bake: Scoop about 2 Tbsp of dough per cookie and place them about 3 inches apart on the prepared baking sheets. Bake 14–15 minutes, or until edges are lightly browned and set. Let cookies cool on the baking sheet for 10 minutes, then transfer to a wire rack to cool fully.

Glaze (Optional): Rewarm or stir the reserved brown butter (for glaze) so it’s liquid. Whisk in confectioners’ sugar, milk, and vanilla until smooth. Dip the top of each cooled cookie into the glaze, then sprinkle a pinch of pumpkin pie spice. Let glaze set before serving.