Preheat your oven to 350°F (175°C) and line a cupcake pan with 12 cupcake liners.

In a large mixing bowl, cream together the unsalted butter and granulated sugar using an electric mixer.

Add the egg, egg yolk, and vanilla extract to the creamed mixture and beat until smooth.

Gradually add the whole milk, sour cream, and canned pumpkin puree, mixing until well combined.

In a separate bowl, whisk together the all-purpose flour, black cocoa powder, pumpkin pie spice, baking powder, baking soda, and salt.

Slowly add the dry ingredient mixture into the wet ingredients, mixing until just combined.

Pour the batter into the prepared cupcake liners, filling each about 3/4 full.

Bake for 17-19 minutes or until a toothpick inserted comes out clean.

Let the cupcakes cool in the pan for about 5 minutes before transferring to a cooling rack.

For the frosting, dry the pumpkin puree on paper towels, then beat the softened butter until fluffy.

Add the cream cheese, dried pumpkin, and spices, then mix well before gradually adding powdered sugar.

Once the cupcakes are cool, pipe the cream cheese frosting onto each cupcake generously.