This cake whips up quickly, but then sits overnight to let the flavors meld. It’s a great holiday or company cake — or a great Monday cake, let’s be real. If you’re not a huge fan of rum, feel free to substitute bourbon or whatever you enjoy — or leave out the alcohol altogether.
1/2 cup (1 stick) butter
6 tablespoons water
1 1/8 cups cake flour
3/4 cup plus 2 tablespoons white sugar
3/4 teaspoon baking soda
1/2 teaspoon salt
1 teaspoon ground cinnamon
1/4 teaspoon nutmeg
1/8 teaspoon ground cloves
1 egg, lightly beaten
1/4 cup sour cream
1 cup pumpkin puree
1/4 cup molasses
3 tablespoons rum
Cinnamon Maple Icing Ingredients:
1/2 cup milk
2 1/2 tablespoons flour
1/2 teaspoon cinnamon
1/4 cup plus 2 tablespoons granulated sugar (not powdered sugar)
1 tablespoons maple syrup
1/2 cup (1 stick) butter, at room temperature
*To toast pecans, bake at 350 degrees F for 5-7 minutes, tossing regularly, until fragrant. Allow to cool completely.
Make the cake: Preheat the oven to 375 degrees and prepare an 8-inch square baking pan (I brush the pan with Wilton’s Cake Release and place a square of greased parchment in the bottom to ensure the cake will come out clean.) In a medium saucepan over medium heat, bring the butter and water to a boil. In the meantime, in a separate large bowl, whisk together the cake flour, sugar, baking soda, salt, cinnamon, nutmeg, and cloves before mixing in the egg, sour cream, pumpkin, and molasses. While mixing, slowly pour in the boiling butter and water mixture. Mix to combine completely. Your batter will be very runny. Pour the batter into the prepared baking pan.
Bake at 375 degrees for 20-23 minutes or until a toothpick inserted in the center comes out with a few moist crumbs. Cool for about 10 minutes before gently poking holes in the cake with a fork. Sprinkle the rum over the top of the cake evenly and allow the cake to cool completely.
Make the frosting: Immediately after leaving your cake to cool, start your frosting, since it will need cooling time as well. Heat the milk, flour, cinnamon, and granulated sugar together over medium heat, whisking constantly. Once it starts to boil, continue whisking and heating it for around 4-5 minutes or until it’s very thick, like cake batter consistency. Remove the mixture from the heat and whisk in the maple syrup. Remove the mixture to a shallow pan and let it cool completely (it’s very important that it’s completely cool, or your frosting will be runny. I let the frosting mixture and the cake both cool for at least 2 hours.)
Once the mixture is cool, beat the butter in the bowl of a stand mixer until soft and fluffy. Add the cooled flour mixture and beat on high until you have fluffy frosting the consistency of stiff whipped cream (this takes several minutes, so be patient). Frost your completely cooled cake and top with toasted pecans and a sprinkling of cinnamon. Let the cake chill overnight in the fridge before serving to let the flavors fully meld, and then let it sit out for at least 30 minutes before serving to let the frosting re-soften.