If your sourdough starter has been silently judging you from the back of the fridge for weeks, this is the recipe that earns its keep. Tender, tangy cake with a swirl of cinnamon sugar and a buttery brown sugar topping — fifty minutes from “I should really feed that thing” to a Saturday morning treat that disappears in twenty.
The discard adds something subtle but real: a soft tang that cuts through the sweetness and a moist, almost cream-cheese-like crumb. You won’t taste “sourdough” — you’ll taste a coffee cake that’s better than the kind made without it.
Best part: it works with discard straight from the fridge. No feeding, no waiting, no fuss.
Why You’ll Love This Recipe
- Built for sourdough discard — the kind that’s been sitting too long
- One bowl, no mixer — just a whisk and a spatula
- Fifty minutes start to finish — including bake time
- Tangy + sweet — the discard balances the sugar in a way regular cakes can’t
- Better the next day — the crumb softens and the flavors deepen overnight
What is Sourdough Discard?
Sourdough discard is the portion of starter you remove before feeding it fresh flour and water. It’s still alive, just less active — and perfect for baking projects where you want the flavor without the rise. Don’t toss it. Bake with it.
This recipe works with discard that’s been refrigerated for up to two weeks. If yours is older or smells sharply alcoholic, give it a sniff test — it should smell tangy and yeasty, not unpleasant. A thin layer of grayish liquid on top (“hooch”) is normal — just stir it back in.
Ingredient Notes
- Sourdough starter or discard — active or unfed both work. Active starter gives a slightly fluffier crumb; discard gives more tang.
- Vegetable oil — keeps the cake moist for days. Don’t substitute butter unless you’re okay with a drier crumb.
- Granulated sugar in the cake, brown sugar in the swirl and topping — the molasses in brown sugar is what makes the crumble taste like a bakery.
- Baking soda (not powder) — sourdough is acidic, so baking soda is the right leavener. It activates the moment it touches the starter.
- Cinnamon — use fresh cinnamon if yours has been in the cabinet over a year. Old cinnamon = flat-tasting cake.
Pro tip: Add 1 teaspoon of vanilla extract to the wet ingredients. It’s not in the original list but it elevates the whole cake.
How to Make It
The technique is straightforward — three quick steps, then bake.
1. Mix wet, mix dry, fold together. Whisk the starter, oil, egg, and vanilla until smooth. In a separate bowl, combine flour, sugar, salt, baking soda, and cinnamon. Pour the dry into the wet and fold gently — don’t overmix. A few flour streaks are fine; they’ll smooth out as the soda activates.
2. Layer the batter and swirl. Use a greased 8×8 square pan or 9-inch round (the original recipe just says “baking pan” — this size matters). Pour half the batter, sprinkle the cinnamon-sugar swirl evenly across the surface, then add the rest of the batter on top.
3. Top, bake, cool. Mix the crumb topping (more on this below) and scatter over the batter. Bake at 350°F. Start checking at 28 minutes — if a toothpick in the center comes out with moist crumbs (not wet batter), it’s done. Cool 10 minutes in the pan before slicing.
Tips for the Best Coffee Cake
- Make a real crumb topping. The original ratio (1 Tbsp flour to 2 Tbsp butter) makes a melted sugar glaze, not crumbs. For true bakery-style crumbs, bump the flour to 1/3 cup. Mix the topping with a fork until it forms pea-sized clumps before scattering.
- Don’t overmix the batter. Sourdough has gluten development built in — overmixing makes the cake tough.
- Pan size is non-negotiable. A 9×13 pan makes this cake thin and dry. 8×8 or 9-inch round only.
- Let it rest 10 minutes after baking. The crumb sets and the swirl solidifies — slicing too early means fall-apart slices.
- Cold discard is fine — but bring the egg to room temperature so the batter doesn’t seize.
Variations to Try
Apple cinnamon: Fold 1 cup of small-diced apples (Granny Smith or Honeycrisp) into the batter before layering.
Brown butter pecan: Brown the butter for the topping, then add 1/2 cup chopped toasted pecans to the crumble.
Espresso glaze: Whisk 1 cup powdered sugar, 2 Tbsp brewed espresso, and 1/2 tsp vanilla. Drizzle over the cooled cake.
Pumpkin spice: Swap 1/4 cup of the sourdough for 1/4 cup pumpkin puree and replace the cinnamon with 1 tsp pumpkin pie spice.
How to Serve It
Best warm, with butter melting on the slice. A splash of cream in your coffee, the cake on a small plate, a quiet kitchen — that’s the whole experience.
For brunch, serve at room temperature with fresh berries and a dollop of crème fraîche. For dessert, warm a slice for 15 seconds in the microwave and add a scoop of vanilla ice cream.
How to Store and Freeze
Counter: Cover tightly and store at room temperature up to 3 days. The flavor deepens by day 2.
Fridge: Up to a week, wrapped well. Bring slices to room temperature or warm briefly before eating — refrigerated coffee cake tastes flat when cold.
Freezer: Wrap individual slices in plastic, then foil. Freeze up to 3 months. Thaw at room temperature for 1 hour, or microwave a frozen slice for 45 seconds.
Frequently Asked Questions
Can I use sourdough discard straight from the fridge?
Yes — that’s exactly what this recipe is designed for. No need to bring it to room temperature.
My discard is two weeks old. Is it still good?
Smell it. If it’s tangy and yeasty, you’re fine. If it smells like rotten cheese or paint thinner, toss it and start fresh.
Do I need to “feed” the starter before using it?
No. This recipe is specifically built for discard or unfed starter. Active starter works too but isn’t required.
Can I make this gluten-free?
Substitute a 1:1 gluten-free flour blend (like Bob’s Red Mill or King Arthur Measure for Measure). The texture will be slightly denser but still good. Note: your starter must also be made from gluten-free flour for the cake to be fully GF.
Why is my cake dense?
Three usual culprits: starter that’s totally dead (no bubbles, smells off), overmixed batter, or expired baking soda. Test your soda by dropping a pinch into vinegar — it should fizz immediately.
Can I bake this in a loaf pan?
Yes, but increase the bake time to 45–50 minutes and start checking at 40. The cake will be denser and the crumble distribution less even.
Sourdough Coffee Cake
Ingredients
For the cake
- 1 cup sourdough starter (discard or active)
- 1/3 cup vegetable oil
- 1 large egg room temperature
- 1 cup all-purpose flour
- 3/4 cup granulated sugar
- 1/2 tsp salt
- 1 tsp baking soda
- 1 tsp ground cinnamon
For the swirl and topping
- 1/2 cup brown sugar for the swirl
- 1 tsp ground cinnamon for the swirl
- 1/2 cup brown sugar for topping
- 2 Tbsp unsalted butter melted
- 1 Tbsp flour for crumble
Method
Preparation
- Preheat your oven to 350°F (175°C). Grease a baking pan.
- In a bowl, whisk together the sourdough starter, vegetable oil, and egg until smooth.
- In another bowl, mix together the flour, granulated sugar, salt, baking soda, and cinnamon.
- Gently fold the dry mixture into the wet mixture until just combined. Be careful not to overmix.
Baking
- Pour half of the batter into the greased pan. Sprinkle evenly with the cinnamon swirl mixture.
- Add the remaining batter on top.
- For the crumb topping, mix together the brown sugar, cinnamon, melted butter, and flour. Crumble this mixture over the top of the batter.
- Bake for about 35 minutes, or until a toothpick inserted into the center comes out clean or with moist crumbs.
- Cool in the pan for a few minutes, then slice and serve warm or at room temperature.