I have made this recipe quite a few times for my Dad's birthday as cupcakes as well as a cake. It tastes great, even to pumpkin haters! My grandmother gave me the recipe.
Line cupcake trays with paper liners (24), or the bottoms of 2 8 inch cake pans with parchment paper, lightly buttered.
Sift flour, cocoa, baking powder, baking soda and salt together and set aside.
Stir the buttermilk, pumpkin and vanilla together in a small bowl and set aside.
Beat the butter and sugars together using a stand mixer on medium speed until light and fluffy.
Beat in the eggs and egg yolk, one at a time.
Reduce mixer speed to low and alternately beat in the flour mixture and the buttermilk mixture in thirds.
Pour the batter into the pans and bake until a toothpick can be inserted into the center and comes out clean. (about 22 minutes for cupcakes, about 35 minutes for a cake).
Cool completely before icing with the Easy Buttercream Icing #425083.
For the cake, after iced, you can cover with a chocolate glaze.
To make the glaze, place the bittersweet chocolate, cold butter and corn syrup in a medium heatproof bowl.
Bring heavy cream to a boil and pour it over the chocolate and let sit for 3 minutes.
Gently stir using a whisk until smooth.
Let sit until thickened, about 3 to 5 minutes.
Pour the glaze onto the center of the iced cake, allowing it to drip over the edges.