1. Preheat oven to 350°F (175°C) and line muffin tins with cupcake liners.
2. Whisk together flour, espresso powder, baking soda, baking powder, pumpkin pie spice, and salt.
3. In a stand mixer, beat pumpkin puree, granulated sugar, brown sugar, and vegetable oil until smooth.
4. Add eggs one at a time, mixing well after each addition.
5. Gradually add the dry ingredients to the wet, mixing until just combined. Avoid overmixing.
6. For extra flavor, add brewed coffee if desired.
7. Fill cupcake liners about ¾ full.
8. Bake for 20-22 minutes or until a toothpick comes out clean.
9. Cool in pans for 10 minutes, then transfer to a wire rack to cool completely. Optionally, brush tops with brewed coffee for moisture and flavor.

For the Espresso Buttercream Frosting:
1. Beat butter on medium speed until creamy.
2. Gradually add confectioners’ sugar, one cup at a time.
3. Mix in espresso powder and vanilla, then add milk until desired consistency is reached.
4. Beat on medium-high speed for 5-8 minutes until fluffy.
5. Pipe or spread on cooled cupcakes.

Alternative Spiced Cream Cheese Frosting:
1. Beat butter, cream cheese, and shortening until smooth.
2. Add powdered sugar and pumpkin pie spice, mixing until fluffy.
3. Chill before piping if needed.