Pumpkin Whoopie Pies

Stir the first 7 ingredients in a large bowl. In a stand mixer fitted with the paddle attachment, beat the butter and both sugars. Gradually add the oil; then add the eggs one at a time, beating between additions. Beat in pumpkin. Add the dry ingredients, alternating with the milk, occasionally scraping down the sides of the bowl. Cover and chill the batter for 1 hour.

Line 2 baking sheets with parchment paper, and spray with nonstick cooking spray. Preheat the oven to 350. Using a small ice cream scoop, spoon batter onto the baking sheets to form little cakes (about 3 tablespoons each), spacing apart. You will have extra batter. With the back of a spoon, smooth the tops of each scoop of batter. Bake the cakes until a toothpick inserted into the centers comes out clean, about 20 minutes, rotating sheets halfway through. Cool the cakes completely. Meanwhile, repeat the process with the remaining batter.

For the filling, combine the butter and powdered sugar in the bowl of a stand mixer. Add the egg whites, vanilla and cream of tartar, and beat until combined. Add milk a little at a time until the filling is spreadable but not runny (you may need a little more or less milk).

Remove the cakes from the baking sheets using a metal spatula. Spoon about 2 tablespoons of the filling onto the flat side of 1 cake. Top with another cake, flat side down. Repeat with the remaining cakes and filling. For extra Halloween spirit, buy some googly-eyed candy at Michaels or HEB and attach them to the pies with a little frosting.