Sweet Potato and Apple Sourdough Discard Coffee Cake

This cake is fall in one bite! This Sourdough Discard Sweet Potato and Apple Coffee Cake is the perfect way to jumpstart the fall baking season. A little bit of brewed coffee is my secret ingredient, adding a little bit to the batter brings out all the earthy flavors and warm spices in the cake.

a full sliced coffee cake on parchment paper on a wooden cutting bard with apples in the background.

Jump to:

Why I love this recipe:
What makes this recipe unique?
What is sourdough discard?
Baking with sourdough discard
What you need
Step-by-step instructions
Recipe FAQs
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Sweet Potato and Apple Sourdough Discard Coffee Cake Recipe

Why I love this recipe:

Sweet potato adds an earthy flavor and moisture to the cake.
Honey crisp apples add sweetness and tartness that make this cake perfect for fall.
Reverse creaming results in a rich, plush crumb.
Great way to use up a lot of leftover sourdough discard - 113 grams (½ cup).
Brown sugar pecan streusel adds a delicious texture to this coffee cake.
Adding coffee to the batter makes this cake unique, a little bit of bitterness and it’s roasted flavor brings out the earthiness of sweet potatoes and warmth of cinnamon.

What makes this recipe unique?

Aside from the addition of sourdough discard, this recipe uses the reverse creaming method. The creaming method commonly starts with beating butter and sugar together until airy. In contrast, the reverse creaming method starts by beating together the flour, sugar, and other dry ingredients with the butter. This results in a mixture that resembles wet sand, and by doing this fat coats the flour which limits gluten development.

Reverse creaming helps cakes from becoming too tough and gummy due to too much gluten forming in the batter. The result is a sturdy bake with a velvety, plush crumb that holds up to all the delicious coffee cake toppings.

Love sourdough cake recipes? Try my recipe for Sourdough Chocolate Cake, Sourdough Pineapple Upside Down Cake and Sourdough Banana Snack Cake.

What is sourdough discard?

Sourdough discard is any portion of your sourdough starter that you do not use to make bread. It’s usually past the point of being viable for bread making since the yeast have exhausted their food source and are considerably weak. There’s more bacterial activity in a sourdough discard so it’s also usually more acidic, this acidity prevents it from growing harmful pathogens like mold or any other microorganisms that may cause spoilage. This is why discard usually has an acidic aroma and flavor, and why it can be kept for long periods of time without being fed.

I usually store my sourdough discard in a food-safe container in the refrigerator until I’m ready to use it. It does not need to be fed at all.

Baking with sourdough discard

Sourdough discard adds a great tangy flavor and moisture to this Sweet Potato and Apple Coffee Cake. Since you’re not using it as a leavener, your sourdough starter does not need to be activated or fed for it to work in this recipe and you can use it straight from the refrigerator.

Older discard will have a tangier, more acidic flavor than freshly-fed sourdough starter. Both will work for this recipe, you’ll get a slightly different flavor but your bake will still be delicious!

Looking for more ways to use sourdough discard? Check out my Favorite Sourdough Discard Recipes!

What you need

This recipe is made up of 3 main components, a pecan streusel, an apple cinnamon topping and a sweet potato cake. There’s a long list of ingredients, but each one plays an important role in making this cake so delicious.

Sourdough discard: Adds a delicious tangy flavor and moisture that keeps this loaf tasting fresher for longer. If you don’t have any sourdough discard, you can use active sourdough starter or add 56 grams of flour and 56 grams of water to your batter.
Sweet potatoes: Adds an earthy flavor and moisture to the cake. Substitute pumpkin puree if that’s all you have.
Apples: Use a baking apple like Honeycrisp or Granny Smith that won’t break down as it bakes.
Coffee: My secret ingredient for this cake! Adding ¼ cup of coffee to the batter brings out the earthy flavors of this cake. Substitute black tea or water if you don’t want to use coffee.
Greek Yogurt: This recipe was developed using vanilla Greek yogurt, which adds both flavor and moisture to the cake. Add ½ teaspoon vanilla extract into the batter if you’re using plain Greek yogurt. Substitute sour cream or strained plain yogurt.
Pecans: Adds texture to your cake. Substitute walnuts or feel free to leave them out if you’re allergic to nuts.
All-purpose flour: The low protein content of all-purpose flour imparts a soft and tender texture to the coffee cake
Baking powder: The main leavener, adds lightness and lift.
Salt: Use sea salt or kosher salt for the best results, different brands of salt have varying grain sizes, so it’s best to weigh your salt instead of measuring with a teaspoon.
Cinnamon: Adds an aromatic flavor to the bread. If you don’t have any on hand feel free to leave it out.
Butter: Tenderizes the crumb, adds moisture and prevents the cake from drying out. Use your favorite plant-based alternative.
Brown sugar: Adds a rich molasses flavor to the apple topping and streusel. Substitute white sugar if that’s all you have
Cane sugar: I prefer cane sugar over white granulated sugar because it is produced using more sustainable methods. Feel free to substitute white sugar, do not use brown sugar because it will add too much moisture and weigh down your cake.
Eggs: Binds the ingredients together, creates structure and stability in the batter. Use large eggs (about 50 grams in the shell).
Powdered sugar: Ensures the streusel doesn’t turn out too hard as it bakes. There’s no substitute for this ingredient.

See recipe card below for a full list of ingredients and measurements.

Step-by-step instructions

Roast sweet potato for 45 mins
Mix apple topping
Mix streusel topping
Cream butter, dry ingredients and sugar
Add egg into the flour mixture
Mix sweet potato, yogurt, coffee and sourdough discard
Fold discard mixture into flour mixture
Pour the batter into a baking pan lined with parchment paper
Bake for 1 hour at 350

Recipe FAQs

Do you leave the skin on the sweet potatoes when this recipe?

It’s best to peel your roasted sweet potatoes before adding it to your batter.

I don’t have enough sourdough discard, can I still make this recipe?

Absolutely! Simply use the same proportion of freshly fed sourdough starter in the recipe. Your starter won’t add a strong tangy flavor to your cake, but will still work.

If you don’t have a starter, but still want to try out this recipe, simply add 56 grams of all-purpose flour and 56 grams of water to your batter.

Why is my coffee cake dense and gummy?

Opening the oven door before your loaf is fully baked could also cause your bread to be too gummy. In this case, your bread will sink and the interior will be gummy.

You may have developed too much gluten in your batter. Be careful not to overmix your batter.

Your baking powder is not fresh. Chemical leaveners have a shelf life, this means that after some time, they lose their abilities to make baked goods rise. If you’ve had yours in your pantry for some time, test them by adding a drop of vinegar to a teaspoon of baking powder. If the mixture fizzes then they are still ok to use.

Why is my coffee cake dry?

This could be the cause of mismeasuring your ingredients or overbaking your cake. For the best results, weigh your ingredients instead of measuring by cups and tablespoons, it’s more accurate. Try your best not to overbake the cake or it will dry out the crumb and the exterior will be too crusty.