Source: http://sallysbakingaddiction.com/2012/10/04/oatmeal-pumpkin-creme-sandwiches/
Ingredients:
Oatmeal Cookies:
1/2 cup butter, softened to room temperature
3/4 cup dark brown sugar
1/2 cup sugar
1 large egg
2 teaspoon vanilla
1/2 teaspoon baking soda
1/2 teaspoon ground cinnamon
1 2/3 cups rolled oats
1 cup flour
Filling:
4 oz cream cheese, softened (half a block)
2 Tablespoons butter, softened
1/4 cup pumpkin puree
1 tsp ground cinnamon
1/4 tsp ground ginger, 1/4 tsp ground cloves, 1/4 teaspoon nutmeg (or 3/4 tsp pumpkin pie spice but then reduce the 1tsp cinnamon by 1/2)
2-2 1/2 cups powdered sugar
flour to thicken if desired
salt, to taste
Directions:
In a large bowl of a stand mixer with paddle attachment or with a handheld mixer, cream the softened butter and sugars until smooth. Add the egg and vanilla and mix well. Slowly stir in the baking soda, cinnamon, oats, and flour. Mix together until just combined. Do not overmix.
Chill the dough for at least one hour in the fridge. Cookies will be very flat if the dough is not cold.
Preheat oven to 325F degrees. Line a cookie sheet with parchment paper or a silicone baking mat (LOVE silicone baking mats). Roll 2 teaspoons of dough (I used a half tablespoon to scoop) into a ball and gently flatten onto prepared sheet. Bake for 9 minutes and let cool on cookie sheet for a minute or two before transferring to a wire rack.
While the cookies are cooling, prepare the pumpkin frosting. Using a mixer, beat all the ingredients together. Use flour to thicken if you need and add salt if you wish to cut some of the sweetness.
Spread a generous amount of frosting on the underside of a cooled cookie and sandwich another cookie on top. Cookies stay fresh for up to 5 days in an airtight container in the refrigerator.