In a mixing bowl, place sugar, flour, baking powder, baking soda, salt, and pumpkin pie spice. Stir with a spoon until well combined. Add in eggs and pumpkin. Mix with an electric mixer until smooth.
1 cup granulated sugar, 3/4 cup all-purpose flour, 1/2 teaspoon baking powder, 1/2 teaspoon baking soda, 1/4 teaspoon salt, 1 heaping tbsp pumpkin pie spice, 3 eggs, 1 cup canned or fresh pumpkin
Divide evenly among 12 muffin cups.
Bake at 350 for 20 minutes, or until the center springs back when lightly pressed. Remove from oven and allow to cool completely.
To make the icing, place butter or margarine, cream cheese, powdered sugar, and vanilla in a mixing bowl. Beat with an electric mixer until smooth and creamy.
8 ounces softened cream cheese, 1 cup powdered sugar, 1/2 cup softened unsalted butter, 1 teaspoon vanilla
To fill cupcakes, place the icing tip or the corner of a freezer-grade zipper seal bag (it is best to enforce the corner of the bag with tape beforehand). Snip off the tip of the bag so that only the very end of the icing tip is sticking out. Fill the bag with half of the icing.
Press the tip down into the center of each cupcake and give a little squeeze to fill. Repeat with all cupcakes. Spread the remaining icing on top of all cupcakes.