Sourdough Pumpkin Bars

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Sourdough pumpkin bars are made with sourdough discard and frosted with a delicious cream cheese frosting. These soft, warmly spiced pumpkin bars bake beautifully in a 10×15-inch jelly roll pan, but can also be made in a half sheet pan for slightly thinner bars.

Sourdough pumpkin bars cut into bars and frosted with cream cheese frosting.

Sourdough discard pumpkin bars are sure to be a fall favorite and a great way to use up extra sourdough starter discard. Another delicious way to use up discard is this sourdough discard pumpkin bread with streusel topping.

There’s just something about fall that makes me want to bake pumpkin into everything, and these sourdough pumpkin bars are only the beginning!

On crisp mornings, I love pulling a tray of Sourdough Pumpkin Scones from the oven, while my Sourdough Pumpkin Roll or Sourdough Pumpkin Pie recipes are perfect for holiday gatherings. When the weekend calls for something extra cozy, bake a pan of Sourdough Pumpkin Cinnamon Rolls to keep the kitchen smelling like autumn all day long.

Why You’ll Love Sourdough Pumpkin Bars

Soft, spiced bars with sourdough goodness: The sourdough discard adds subtle tang and moisture, making these bars extra tender and flavorful.
Perfect pumpkin spice balance: A cozy mix of cinnamon and pumpkin pie spice brings just the right amount of warmth without being overpowering.
Luscious cream cheese frosting: It’s the perfect topping for the spiced pumpkin base.
Great for sharing: Baked in a jelly roll pan, this recipe makes plenty of bars—perfect for gatherings and holidays.

Ingredients

Find the full list of ingredients, amounts, and instructions in the recipe card at the bottom of this post.

Pumpkin Purée: Brings moistness, rich flavor, and that classic pumpkin taste we love in fall desserts. It’s not hard to make your own homemade pumpkin puree!
Sourdough Discard: You can also use active sourdough starter, but be sure to add the baking powder and baking soda.
Brown Sugar: Gives warmth and depth of flavor, pairing perfectly with the pumpkin spice.
Pumpkin Pie Spice: A cozy blend of cinnamon, nutmeg, and cloves that makes each bite taste like fall. I like to make homemade pumpkin pie spice.
Eggs: Provide structure and help the bars rise beautifully while staying moist.
Cream Cheese: The star of the frosting, lending a smooth, tangy sweetness that complements the spiced pumpkin base.

Equipment

Jelly Roll Pan (10×15-inch) or alternative (see notes below for other pan alternatives).

How to Make This Sourdough Pumpkin Bars Recipe

Here are the step-by-step instructions for making pumpkin bars with sourdough discard.

Collage of four photos showing steps 1-4 of how to make sourdough pumpkin bars.

Make the Bars:

Preheat oven to 350°F (175°C). Grease or line a 10×15-inch jelly roll pan with parchment.
In a large bowl, whisk together the pumpkin purée, granulated sugar, brown sugar, oil, eggs, vanilla, and sourdough discard until smooth (Photo 1).
In a separate bowl, whisk together the flour, cinnamon, pumpkin pie spice, baking powder, baking soda, and salt (Photo 2).
Add the dry ingredients to the wet ingredients (Photo 3) and stir just until combined (Photo 4).
Pour the batter into the prepared pan and spread into an even layer (Photo 5).
Bake for 20–25 minutes, or until a toothpick inserted in the center comes out clean (Photo 6). Let the bars cool completely before frosting.

Collage of four photos showing steps 5-8 of how to make sourdough pumpkin bars.

Make the Frosting:

In a large bowl, beat the softened cream cheese and butter together until smooth and fluffy, about 2–3 minutes.
Add the vanilla, salt, and optional cinnamon or pumpkin pie spice. Mix to combine.
Gradually beat in the powdered sugar, starting with 3 cups and adding up to 3¼ cups for your desired sweetness and consistency. If needed, add a small splash of milk or cream to loosen the frosting (Photo 7).
Spread the frosting evenly over the cooled pumpkin bars (Photo 8). For neater slices, chill for 15–20 minutes before cutting.
Cut into bars and serve (Photos 9-12). These would go well with a Homemade Pumpkin Spice Latte or a London Fog Tea Latte.

Collage of four photos showing steps 9-12 of how to make sourdough pumpkin bars.

Tips & Notes

For best results, bake until the center reaches an internal temperature of 200°F–205°F. This ensures the bars are fully set without overbaking.
For this recipe, you can use a whisk to mix the dry ingredients and the wet ingredients. Then switch to a spatula for combining the wet and the dry ingredients so that they do not over-mix. You may use a hand mixer or a stand mixer if you want, but be sure not to overmix and work on a lower speed.

Pan Options

Jelly roll pan (10×15-inch): The standard for this recipe. This ratio is ideal and helps create the perfect amount of cake and frosting ratio.
Half-sheet pan (13×18-inch): If you prefer thinner bars, you can use a half-sheet pan. Start checking for doneness around 16 – 18 minutes.
9×13-inch baking pan: Great for thicker, more cake-like bars. Bake time will increase to about 28–32 minutes. Check the center for doneness with a toothpick.

Decorating Ideas

These bars are great as is, but if you want to take them to the next level, you could try the following decorating ideas below:

Dust the top lightly with cinnamon or pumpkin pie spice.
Reserve a small batch of extra frosting to pipe tiny pumpkins.
Sprinkle with chopped pecans or cinnamon sugar for extra texture and a festive finish.

Storage & Reheating

Store frosted bars in an airtight container in the fridge for up to 5 days. Let them sit at room temperature for 10–15 minutes before serving.
Unfrosted bars can be wrapped and frozen for up to 2 months. Thaw in the fridge, then frost before serving.
You can bake and frost them a day ahead. They slice even cleaner when chilled.

Frequently Asked Questions

Can I use active starter instead of discard?

Yes, either works in this recipe. It won’t affect the final flavor or texture.

Can I skip the frosting?

You can, but the cream cheese frosting adds richness and balances the spice. A dusting of powdered sugar or a simple glaze would work as a lighter alternative.

What if I don’t have a jelly roll pan?

No problem, you can make this in a half-sheet pan or a 9×13 pan. Please see the notes above for alternative pans and bake times.

Can I make these dairy-free?

Yes—use a dairy-free cream cheese and butter for the frosting.