Pumpkin Whoopie Pies

Preheat oven to 350° and line two large baking sheets with parchment paper. In a medium bowl, whisk together flour, pumpkin spice, salt, baking powder, and baking soda. In a separate large bowl using a hand mixer, beat brown sugar, vegetable oil, 1/2 cup butter, pumpkin puree, eggs, and 1 teaspoon vanilla until smooth. Add dry ingredients and stir until combined. (The dough will be sticky and soft.) Using a medium cookie scoop, scoop dough onto prepared baking sheets, leaving at least 2” between each cookie. Bake until springy to touch, about 15 minutes. Transfer cookies to a cooling rack to cool completely. Make filling: In a large bowl using a hand mixer, beat together remaining 1/2 cup butter and cream cheese. Add powdered sugar, maple syrup and remaining 2 teaspoons vanilla and beat until fluffy. Spread filling onto the bottoms of half of the cookies. Place the remaining cookies, bottom side-down, on top. Serve immediately or store in fridge in an airtight container for 2 to 3 days.