Brown butter for the cream filling: Add butter to a saucepan over medium heat. Melt then cook for 6-8 minutes while stirring often. It will begin to foam and turn brown.
½ cup butter
Once the foam reduces and you see brown milk solids at the bottom, remove from heat and chill in the fridge while you make the cookies until it solidifies into softened butter. You’ll use the chilled butter for the cream filling.
Preheat the oven to 350 degrees F and line a large baking sheet with parchment paper. In a large bowl, add softened butter, brown sugar, and granulated sugar. Cream together until light and fluffy.
1/2 cup butter, ⅓ cup brown sugar, ⅓ cup granulated sugar
Add pumpkin puree, egg yolk, vanilla extract, and mix until combined.
⅓ cup pumpkin puree, 1 egg yolk, 1 tsp vanilla extract
In a separate bowl, stir together flour, pumpkin pie spice, cinnamon, baking soda and sea salt. Add this mixture to wet ingredients and stir until just combined.
1 cup gluten free all-purpose flour, 2 tsp pumpkin pie spice, ¼ tsp cinnamon, ½ tsp baking soda, ¼ tsp sea salt
Fold in oats until just combined.
1 ½ cup old fashioned oats
Scoop dough with a 1½ tbsp cookie scoop or by rounded tablespoons, roll into balls, and place them on the parchment lined baking sheet about 2 inches apart. Use the flat side of your palms or a greased bottom of a mug to flatten the dough to about ¼ inch thick.
Bake for 9-11 minutes until the edges are golden. Cool for 5 minutes then transfer to a wire rack to cool completely. You can check on the chilled brown butter while the cookies cool and if it’s too cold and hard, let it sit at room temperature to soften.
Once the cookies are fully cooled, beat the softened browned butter with an electric mixer for a minute until smooth. Add in powdered sugar, milk, and vanilla extract, and beat on low until the sugar is fully incorporated. Increase to medium-speed and beat for another 3 minutes until nice and fluffy.
2 cups powdered sugar, 1 tbsp dairy free milk, 1 tsp vanilla extract
Spread or pipe the cream filling to the bottom of a cookie, then press another cookie on top to make a sandwich. Repeat with the rest of the cookies. Enjoy!