This pumpkin sheet cake is one of my new favorite things. I am decidedly NOT a pumpkin person (sorry, haters) particularly in the form of pie. But in cake (or mousse!) – well, that’s a whole other story. Pumpkin makes for the moistest of cakes (my most beloved kind). And I love sheet cakes for their height and old-school good looks, which this cake has in spades.
I developed this pumpkin sheet cake recipe for the November issue of Main Street Magazine (where I write a monthly column) and I figured it had better be Thanksgiving appropriate (spoiler alert: it is). The cake works brilliantly for those bakers amongst us who aren’t pumpkin fans, but understand that others sitting around our holiday tables likely are (read: mothers-in-law). And, because it is a little unusual for Thanksgiving (ie: it’s not a pie) you don’t have to feel bad about generously frosting it in chocolate buttercream, with bourbon no less. 
Chocolate and Pumpkin are a fabulous combo and the Bourbon adds that little something special, that won’t be missed if omitted, but if included is much appreciated. It was a fluke, in fact, that it made it into the buttercream in the first place. I was always planning on a chocolate frosting, but when I stumbled upon a tub of the stuff in my fridge, WITH bourbon (I had frosted these with it, if you must know) I knew it was destined to top my bright orange showstopper of a cake.
Pumpkin Sheet Cake with Chocolate Bourbon Buttercream
Ingredients
For the cake:
- 2 cups all-purpose flour
- 1 cup cake flour sifted
- 2 tsps baking powder
- 1/4 tsp baking soda
- 1 tsp table salt
- 2 tsps cinnamon
- 3/4 tsp nutmeg
- 1/2 tsp ginger
- 1 cup vegetable oil
- 1 1/2 cups granulated sugar
- 1 cup light brown sugar
- 2 tsp pure vanilla extract
- 2 eggs
- 2 egg yolks
- 1 15 oz can pumpkin puree
For the frosting:
- 7 tbsp unsalted butter softened
- 2 cups confectioners' sugar
- 1/2 cup Dutch-process cocoa powder
- 2 1/2 tbsps bourbon
- 2 tbsps heavy cream
- 1 1/2 tsps pure vanilla extract
Instructions
To make the cake:
- Preheat the oven to 350°F. Grease a13-by-9-by-2-inch pan with cooking spray or softened butter. Line the bot-tom with parchment paper and grease again. Set aside.
- Whisk the all-purpose flour, cake flour, baking powder, baking soda, salt, and spices in a medium-sized bowl, and set aside.
- Place the oil, granulated sugar, brown sugar, and vanilla in a large bowl. Whisk to combine. Add the eggs and yolks, and continue whisking until smooth. Add the pumpkin and whisk again.
- Add the dry ingredients to the wet, and using a rubber spatula, gently fold to combine. Do not over mix. Scrape the batter into the pre-pared pan and smooth the top with an offset spatula or butter knife.
- Bake for 25-30 minutes, rotating at the halfway point, until a cake tester comes out with a moist crumb or two.Let cool until easy to handle before inverting the cake on to a cooling rack and then flipping it right side up to cool to room temperature
To make the frosting:
- Place the room temperature butter in the bowl of a stand mixer, fitted with the paddle attachment. Mix on medium speed until the butter is smooth.
- Meanwhile, sift the confectioners’ sugar and cocoa powder together in a large bowl. On medium-low speed, add a little of the sugar/cocoa mixture to the butter.
- Once incorporated, stop the mixer and scrape the bowl with a rubber spatula, and continue to add and stop and scrape, until all of the dry ingredients are incorporated. Add the bourbon and then slowly add the cream. Stop the mixer and scrape the bowl again. Add the vanilla and then beat the mixture on medium speed until the frosting is light and fluffy, about 3 to 5 minutes. Don’t be afraid to beat longer than you might think necessary – this ensures an airy frosting.
- Generously spread the cake with the frosting, leaving the sides bare, if you so desire. If you’d like to freeze the cake, do so after frosting it, cover-ing it in plastic wrap only once it is frozen solid. Remove the plastic wrap and let come to room temperature before serving.
- The cake will keep wrapped in plastic wrap on the counter for up to three days, and is even more delish on day two.