Sourdough Discard Brown Sugar Banana Snack Cake (No Frosting) – Soft, Cozy, and Simple

This is the kind of snack cake you make on a quiet afternoon and then wonder how it disappeared so fast. It’s soft, lightly caramelized from brown sugar, and full of banana flavor. The sourdough discard adds a gentle tang that keeps it from being too sweet and makes the crumb extra tender.

No frosting here—just a golden top and maybe a sprinkle of sugar before baking. It’s easy, wildly snackable, and perfect for using up that sourdough discard you’ve been saving.

Why This Recipe Works

The combination of ripe bananas and brown sugar creates a moist, flavorful cake with toffee-like notes. Sourdough discard brings a subtle tang and helps the cake stay tender for days.

Oil instead of butter keeps things soft and simple, and it mixes smoothly with the bananas. A blend of cinnamon and vanilla rounds it out, making it taste like a cozy banana bread meets snack cake.

You don’t need frosting because the texture and flavor do the heavy lifting. The top bakes into a lightly crackled, golden surface that feels complete on its own.

It’s pantry-friendly, fuss-free, and reliable every time.

Shopping List

• Ripe bananas (3 medium, very spotty)
• Brown sugar (light or dark)
• Sourdough discard (100% hydration)
• All-purpose flour
• Baking powder
• Baking soda
• Kosher salt
• Cinnamon (optional but recommended)
• Neutral oil (like canola, grapeseed, or light olive oil)
• Eggs
• Vanilla extract
• Plain yogurt or sour cream (adds moisture)
• Turbinado sugar (optional, for topping)

How to Make It

1. Preheat and prep: Heat the oven to 350°F (175°C). Grease an 8×8-inch square pan and line with a parchment sling for easy removal.
2. Mash bananas: In a large bowl, mash 3 very ripe bananas until mostly smooth with small lumps for texture.
3. Add wet ingredients: Whisk in 3/4 cup packed brown sugar, 1/2 cup neutral oil, 2 large eggs, 1 teaspoon vanilla, 1/2 cup sourdough discard, and 1/3 cup plain yogurt or sour cream. Mix until glossy and combined.
4. Combine dry ingredients: In a separate bowl, whisk 1 1/2 cups all-purpose flour, 1 teaspoon baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon kosher salt, and 1 teaspoon cinnamon.
5. Bring it together: Add the dry ingredients to the wet.

   Stir gently with a spatula until just combined. Do not overmix; a few streaks are okay.

6. Pan and sprinkle: Pour the batter into the prepared pan. Smooth the top.

   Sprinkle 1–2 tablespoons turbinado sugar for a crisp lid (optional).

7. Bake: Bake for 28–35 minutes, until the center is set and a toothpick comes out with a few moist crumbs. The top should be golden and slightly crackly.
8. Cool: Let the cake cool in the pan for at least 20 minutes. Lift it out with the sling and cool a little longer before slicing into squares.
9. Serve: Enjoy warm or at room temperature.

   It’s perfect plain, or with a swipe of butter if you want a little extra richness.

How to Store

Keep the cake covered at room temperature for up to 3 days. The sourdough and bananas keep it moist and soft. For longer storage, wrap slices individually and refrigerate for up to 5 days.

Warm briefly in the microwave to refresh.

To freeze, wrap slices tightly and store in an airtight bag for up to 2 months. Thaw at room temperature or microwave in short bursts until soft.

Benefits of This Recipe

• Uses sourdough discard: Reduces waste and adds flavor without extra effort.
• No mixer needed: Two bowls, a whisk, and a spatula are all you need.
• Moist, not dense: Oil and yogurt keep the crumb soft without heaviness.
• Not too sweet: Brown sugar and tangy discard balance each other nicely.
• Everyday-friendly: Bakes quickly, slices cleanly, and travels well in lunchboxes.

What Not to Do

• Don’t use under-ripe bananas. You need soft, spotty bananas for sweetness and moisture.
• Don’t overmix the batter. Overmixing develops gluten and leads to a tough cake.
• Don’t skip the salt. It sharpens the flavors and keeps the sweetness in check.
• Don’t rely on discard for leavening. You still need baking powder and baking soda.
• Don’t overbake. Pull it when the center is set and a few moist crumbs cling to the tester.

Alternatives

• Flour: Swap up to half the all-purpose flour with white whole wheat flour. Add 1 tablespoon extra yogurt if the batter seems thick.
• Sugar: Use coconut sugar for a deeper caramel note.

  You can cut the sugar to 1/2 cup for a less sweet cake.

• Fat: Melted butter works instead of oil for a richer flavor. Use the same amount.
• Add-ins: Stir in 1/2 cup chocolate chips, chopped walnuts, or toasted pecans. Keep add-ins modest so the cake stays tender.
• Spices: Try a pinch of nutmeg or cardamom with the cinnamon for a warm twist.
• Dairy-free: Use a dairy-free yogurt and neutral oil.

  The texture will still be soft.

• Pan size: Double the recipe for a 9×13-inch pan and bake 32–40 minutes. For muffins, bake 16–20 minutes.

FAQ

What is sourdough discard, and does it need to be active?

Sourdough discard is unfed starter that you remove before feeding your sourdough. It doesn’t need to be bubbly or active for this recipe.

Its job here is flavor, moisture, and tenderness—not rise.

Can I make this cake gluten-free?

Use a 1:1 gluten-free all-purpose blend that includes xanthan gum. Check doneness a few minutes early, as gluten-free cakes can brown faster on the edges.

Do I need both baking powder and baking soda?

Yes. The baking soda reacts with the acidity from the sourdough discard and yogurt, helping with lift and browning.

Baking powder ensures a reliable rise throughout.

How ripe should the bananas be?

Very ripe—deeply speckled or almost black. The riper they are, the sweeter and more flavorful your cake will be.

Can I reduce the sugar?

Yes. Reduce to 1/2 cup for a lightly sweet cake.

The texture will still be moist, especially with the bananas and yogurt.

Why is there no frosting?

This cake is designed to be a snack—simple, portable, and not too sweet. The turbinado sugar on top gives a delicate crunch, and the brown sugar caramelizes enough that frosting isn’t missed.

Can I make it ahead?

Absolutely. The flavor is even better the next day.

Store tightly wrapped at room temperature, then slice as needed.

What if I don’t have yogurt or sour cream?

Use buttermilk in the same amount, or mix 1/3 cup milk with 1 teaspoon lemon juice and let it sit for 5 minutes. This keeps the batter balanced and tender.

Why is my cake dense?

Common culprits are under-ripe bananas, overmixing, or expired leaveners. Measure flour correctly by fluffing, spooning, and leveling to avoid packing too much into the cup.

Can I add a streusel topping?

Yes, but keep it light so it doesn’t weigh down the cake.

A simple mix of brown sugar, flour, and butter works. Bake until the center is set.

In Conclusion

This Sourdough Discard Brown Sugar Banana Snack Cake is the kind of effortless baking that feels like a win every time. It’s moist, gently sweet, and deeply comforting, with no frosting or fancy steps.

Whether you’re using up discard or craving something cozy, this cake fits the moment. Slice it warm, share it generously, and enjoy how quickly it becomes a house favorite.