Sourdough Pumpkin Sheet Cake with Cream Cheese Frosting

square of pumpkin cake on wooden surface

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5 from 4 votes

Sourdough Pumpkin Sheet Cake with Cream Cheese Frosting

Sweet pumpkin spice mixed with tangy sourdough starter combine to form this moist, easy to make sourdough pumpkin cake.

Prep Time20

Cook Time30

cooling1

Total Time1 50

Course: Dessert

Cuisine: American

Keyword: Fall, sourdough cake recipe, sourdough discard recipe

Servings: slices

Calories: 421kcal

Author: Katie

Equipment

Rimmed sheet pan
Hand mixer
Large mixing bowl

Ingredients

Cake

2 cups sugar
1 cup vegetable oil
2 cups pureed pumpkin 1 (15 ounce) can
4 eggs
1 ¾ cups all purpose flour
2 teaspoons baking soda
2 teaspoons baking powder
½ teaspoon salt
2 teaspoons cinnamon
¼ teaspoon cloves
¼ teaspoon allspice
1/2 cup sourdough starter discard (unfed is fine)

Frosting

10 tablespoons melted butter
8 ounces cream cheese
4 cups powdered sugar
1 dash vanilla

Instructions

Preheat oven and prepare pan. Preheat your oven to 350°F (175°C) and place the rack in the middle. Then, coat a 10x15-inch jelly roll pan with nonstick cooking spray.
Make the batter. In a large mixing bowl, use an electric hand mixer on medium speed to beat together the canned pumpkin, sugar, and oil until well combined. Add the eggs one at a time, beating until each egg is fully incorporated and scraping down the bowl as necessary. In a separate bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, cloves, and allspice. Gradually add the dry ingredients to the pumpkin mixture, mixing on low speed until just combined.
Stir in the sourdough starter. Mix in the sourdough starter by hand, making sure it's completely mixed into the batter. Scrape down the sides and bottom of the bowl so everything is well combined.
Bake and cool. Pour the batter into the prepared pan, spreading it out evenly. Bake in the preheated oven for 25-30 minutes or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan on a wire rack. After 15 minutes, cover the cake with a clean tea towel to prevent it from drying out.
Make the frosting. Once the cake is completely cooled, prepare the frosting. Blend the melted butter, cream cheese, and vanilla with a mixer until fluffy. Gradually add the powdered sugar, beating until smooth. If the frosting is too thick, add a splash of milk to reach the desired consistency.
Serve. Spread the frosting over the cooled cake and serve directly from the pan. Refrigerate any leftovers.

Notes

Make sure all your ingredients, like eggs and cream cheese, are at room temperature to help them mix more smoothly into the batter and frosting.

When you mix the dry ingredients with the wet ones, mix until everything is just combined. Mixing too much can make the cake tough instead of soft and moist.

You can bake this cake in a rimmed sheet pan or a 13 x 9 baking dish.

If your frosting is too thick, add a splash of milk to get the right consistency. If it's too thin, add some more powdered sugar.

If your cake looks a bit uneven when you take it out of the oven, don't worry. It will even out as it cools.

Nutrition