Preheat oven: Set oven to 350°F and line baking sheets with parchment paper.
Mix wet ingredients: In a large bowl, beat butter, egg, vanilla, and sugar with an electric mixer until well combined. Mix in pumpkin until fully incorporated.
Combine dry ingredients: In another bowl, whisk together flour, oats, baking powder, cinnamon, nutmeg, and cloves.
Form dough: Add dry ingredients to wet ingredients and mix until a soft dough forms.
Shape cookies: Scoop 2-tablespoon portions of dough, place evenly on prepared baking sheets, and gently press down. You should have 16 cookies.
Bake: Bake for 10 minutes or until bottoms are golden brown. Transfer to a wire rack to cool completely.
Make frosting: Beat butter, cream cheese, vanilla, and powdered sugar until smooth and fluffy.
Assemble cream pies: Pipe or spread frosting onto the bottom of 8 cookies. Top with remaining cookies to create sandwiches.