Sourdough Discard Coffee Cake
This Sourdough Discard Coffee Cake is a tender, buttery sheet cake with a hidden cinnamon filling and a thick, golden crumble topping. It comes together in minutes and is the perfect way to use up your sourdough discard — no yeast, no rise time, just pure cozy comfort.
Servings: 14 squares
Equipment
- 1 Stand mixer with paddle attachment
- 1 11x8-Inch Baking Dish or similar size
- Parchment Paper
- Mixing Bowls
- 1 Microwave-Safe Bowl for melting butter
Ingredients
Crumble Topping
- 4 tablespoons unsalted butter melted
- ½ cup brown sugar packed
- ½ cup all-purpose flour
- 2 teaspoons cinnamon
Cinnamon Filling
- ⅓ cup brown sugar packed
- ⅓ cup all-purpose flour
- 2 teaspoons cinnamon
Coffee Cake Batter
- ½ cup unsalted butter softened
- ½ cup brown sugar packed
- ½ cup granulated sugar
- 2 large eggs
- 1 teaspoon vanilla extract
- ¼ cup sour cream
- ¼ cup sourdough discard unfed, straight from fridge
- 1 cup whole milk or buttermilk
- 1 teaspoon salt
- 2 teaspoons baking powder
- 2 cups all-purpose flour
Instructions
Make the Crumble Topping
- Preheat the oven to 350°F. Spray or line an 11x8-inch baking dish with parchment paper and set aside.
- In a medium microwave-safe bowl, melt the butter. Add the brown sugar, flour, and cinnamon.
- Use a fork to stir and break up any clumps until the mixture is combined and crumbly. Set aside to cool while you prepare the rest.
Make the Cinnamon Filling
- In a small bowl, combine the brown sugar, flour, and cinnamon. Stir well and set aside until needed.
Make the Batter
- In the bowl of a stand mixer fitted with the paddle attachment, combine the softened butter, granulated sugar, and brown sugar. Cream on medium speed until smooth and fluffy, about 2–3 minutes.
- Add the eggs and vanilla extract. Mix until fully combined, scraping down the sides of the bowl as needed.
- Add the sour cream, milk (or buttermilk), and sourdough discard. Mix well, scraping down the sides often.
- Add the flour, salt, and baking powder. Mix on low until just combined, then increase to medium and mix until the batter is smooth. Scrape down the sides as needed.
Assemble and Bake
- Pour approximately half of the batter into the prepared baking dish and spread it evenly to the sides.
- Sprinkle the cinnamon filling evenly over the batter layer.
- Pour the remaining batter over the cinnamon filling and carefully spread it to the edges, covering the filling completely.
- Sprinkle the cooled crumble topping evenly over the top of the batter.
- Bake in the preheated oven for 40–45 minutes, or until golden brown and the center is set. A toothpick inserted in the center should come out with just a few moist crumbs.
- Remove from the oven and allow to cool completely before slicing into squares.
Notes
Storage: Store in an airtight container at room temperature for up to 3 days. Wrap individual slices tightly and freeze for up to 2 months.
Tip: Use room temperature butter — cold butter will not cream properly and will result in a dense cake.
Tip: Let the crumble cool before adding it to the batter. Warm crumble will melt into the batter instead of staying on top as a distinct layer.
Tip: Sourdough discard adds subtle tang and moisture. Unfed discard straight from the fridge works perfectly — this is not a leavened recipe.
Tip: The cake is done when the center is set and a toothpick comes out with just a few moist crumbs. Don't overbake — it continues to cook as it cools.
Tip: Buttermilk can be substituted for the whole milk for an even more tender crumb.
