Preheat your oven to 350°F. Line a 12-cupcake pan with liners.

In a small bowl, whisk together the cake flour, baking powder, baking soda, salt, and pumpkin pie spice.

In a large bowl, cream the softened butter and granulated sugar with an electric mixer on high speed until fluffy, about 2 minutes.

Add the egg and vanilla and mix on medium speed for 1-2 minutes until the mixture is pale and fluffy.

Mix in the canned pumpkin puree on low speed. Set aside.

Gradually add the dry ingredients and buttermilk to the wet ingredients, mixing until combined.

Fill each cupcake liner ¾ full using a large cookie scoop.

Bake for 17-19 minutes, until a toothpick inserted in the center comes out clean. Let the cupcakes cool in the pan for 10 minutes, then transfer them to a cooling rack to cool completely.

While the cupcakes cool, make the frosting. Beat the softened butter in a large bowl with an electric mixer on high speed until pale and fluffy, about 5 minutes.

Add the cold cream cheese and mix on medium speed until combined.

Gradually sift in the powdered sugar, mixing on low speed until fully combined.

Mix in the pumpkin pie spice on high speed until the frosting is light and fluffy, 1-2 minutes. Start with 1 teaspoon and add more to taste.

Transfer the frosting to a piping bag fitted with a decorative tip (like the Wilton 1M).

Once the cupcakes are completely cool, pipe a generous amount of frosting onto each one.

Serve and enjoy! Store any leftovers in an airtight container in the fridge for up to three days.