Name: Vegan Sourdough Banana Bread
Prep time: 15 min
Cook time: 60 min
Total time: 75 min
Ingredients: 1 cupsourdough starter; 3 large ripe bananas; 1 Tbspground flax seed; 3 Tbspwater; 2 Tbspavocado oilor melted coconut oil; 1 tsppure vanilla extract; 1/2 cupcoconut sugaror brown sugar; 1 cupgluten-free all-purpose flouror regular flour; 1 tspbaking soda; 1/2 tspsea salt; 2 tspground cinnamon; 3/4 cupraw walnutschopped

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This loaf is one of those recipes I reach for when I have overripe bananas and an active sourdough starter that needs some love. It’s straightforward, forgiving, and keeps well — which makes it perfect for weekday breakfasts or a relaxed weekend bake. The crumb is tender, the cinnamon adds warmth, and the walnuts give a welcome crunch.

I developed this version to be entirely plant-based and adaptable: you can use gluten-free all-purpose flour or regular flour, avocado oil or melted coconut oil, and coconut sugar or brown sugar. The flax “egg” binds the batter without dairy or eggs, and the sourdough starter contributes subtle tang and lift. No complicated folds, no long proofing — just a simple mix-and-bake approach.

Below you’ll find the shopping list, the exact step-by-step process (kept to the source directions), plus tips for equipment, storage, troubleshooting, and seasonal serving ideas. Read the process through once before you start, then get your bowls and loaf pan ready.

Shopping List

1 cup sourdough starter — provides lift, flavor and moisture; use an active (recently fed) starter for best results.
3 large ripe bananas — the sweeter and more spotted the bananas, the better the banana flavor and natural sweetness.
1 Tbsp ground flax seed — mixed with water it becomes a binder to replace eggs.
3 Tbsp water — used to hydrate the ground flax seed and activate the flax “egg.”
2 Tbsp avocado oil or melted coconut oil — oil keeps the crumb tender; choose avocado oil for a neutral taste or coconut oil for a hint of coconut.
1 tsp pure vanilla extract — enhances and rounds the flavors.
1/2 cup coconut sugar or brown sugar — adds sweetness and color; coconut sugar is less refined, brown sugar adds molasses notes.
1 cup gluten-free all-purpose flour or regular flour — the base; use a cup-for-cup gluten-free blend if needed.
1 tsp baking soda — single-acting leavener that reacts with the acids in the starter and bananas for lift.
1/2 tsp sea salt — balances sweetness and highlights flavors.
2 tsp ground cinnamon — warms and complements the banana.
3/4 cup raw walnuts chopped — adds texture and a toasty finish; reserve a few pieces if you want to sprinkle on top before baking.

Cooking (Vegan Sourdough Banana Bread): The Process

Preheat the oven to 350°F (175°C). Lightly spray a 9″ x 5″ loaf pan with cooking oil.
In a small bowl, stir together 1 Tbsp ground flax seed and 3 Tbsp water. Set aside for 10–15 minutes, stirring occasionally, until thickened to the consistency of a beaten egg.
In a large bowl, whisk together 1 cup gluten-free all-purpose flour or regular flour, 1 tsp baking soda, 1/2 tsp sea salt, and 2 tsp ground cinnamon.
In a medium bowl, mash 3 large ripe bananas with a fork until mostly smooth. Add 1 cup sourdough starter, the flax seed mixture, 2 Tbsp avocado oil or melted coconut oil, 1 tsp pure vanilla extract, and 1/2 cup coconut sugar or brown sugar. Whisk or stir until well combined.
Pour the wet mixture into the dry ingredients and stir gently until just combined. Do not overmix.
Fold in 3/4 cup raw walnuts, chopped. If you want walnuts on top, reserve some of the chopped walnuts from this amount and sprinkle them on the batter before baking.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake on the middle rack for 50–60 minutes, until a toothpick inserted into the center comes out clean or with only a few moist crumbs.
Remove the pan from the oven and let the bread cool in the pan for 10–15 minutes. Then remove the loaf from the pan and transfer it to a wire rack to cool completely before slicing.

Why It’s My Go-To

This recipe works because it balances simplicity with reliable technique. You don’t need to babysit a long fermentation; the starter contributes flavor and a bit of lift without the time commitment of sourdough-proofed breads. It’s vegan, which makes it inclusive for households with different dietary choices, and the ingredient swaps are flexible without derailing the final texture.

It’s also forgiving. Overripe bananas are meant for this loaf, and a slightly heavier hand when folding the batter won’t ruin the crumb. If you keep a starter in your fridge, this is a beautiful way to use a discard or refresh it by feeding and using an active portion.

International Equivalents

Measurements here are in US cups and teaspoons. If you cook with grams, roughly translate 1 cup flour to 120–130 g depending on how you measure it (scooped vs. spooned). One cup of sourdough starter equals about 240 g. For smaller ovens or different pan sizes outside the US, a standard 9″ x 5″ loaf pan is common — if you use a slightly larger or smaller pan, adjust the bake time and watch for doneness.

For sugar choices: coconut sugar and brown sugar are used interchangeably in the recipe. In places where those aren’t common, use a similar unrefined sugar or cane sugar at the same volume. For oil, a neutral vegetable oil can stand in for avocado oil; melted coconut oil is optional if you want the faint coconut note.

Equipment & Tools

9″ x 5″ loaf pan — the pan size determines the bake time and loaf shape.
Oven — preheated to 350°F (175°C).
Mixing bowls — one small for the flax “egg,” one large for dry ingredients, one medium for wet.
Fork or potato masher — to mash the bananas.
Whisk and spatula — whisk the dry mix and fold batter gently.
Measuring cups and spoons — for accurate amounts.
Cooking oil spray — to grease the loaf pan lightly.
Wire rack — for cooling the loaf completely before slicing.

What Not to Do

Do not skip the flax seed step. The flax “egg” is the binder in this vegan recipe and affects structure.
Do not overmix once you combine wet and dry. Overmixing develops more gluten (if using regular flour) and can make the loaf dense.
Do not open the oven repeatedly during the first 30–40 minutes. Dropping the oven temperature or letting heat escape can affect rise and texture.
Do not slice the loaf while it’s still very hot. It needs to cool on a wire rack to set the crumb and avoid a gummy center.

Seasonal Serving Ideas

Spring: Serve slightly warm slices with a smear of vegan cream cheese and a few fresh berries on the side for brightness. The loaf’s cinnamon plays well with the berries’ acidity.

Summer: Toast thin slices and top with a smear of almond butter and a drizzle of date syrup or thin maple syrup for a quick outdoor breakfast. Add thinly sliced banana or grilled peaches for a seasonal twist.

Autumn/Winter: Warm slices and top with softened vegan butter or a scoop of nondairy yogurt and a sprinkle of toasted chopped walnuts and cinnamon. The loaf pairs beautifully with hot tea or a spiced latte.

Notes on Ingredients

Sourdough starter — Use an active starter if possible. If you want to use discard, make sure it’s still reasonably lively for flavor. The starter adds acidity and depth beyond what commercial yeast would provide.

Bananas — The bananas are both sweetener and moisture. Mash them until mostly smooth to avoid large chunks. If you prefer visible banana pieces, leave some texture.

Ground flax seed + water — This combination thickens to an egg-like consistency. Stir occasionally during the 10–15 minutes to ensure it gels evenly.

Oil — 2 Tbsp keeps the loaf moist. Avocado oil is neutral; coconut oil adds a mild coconut scent and firmer texture at room temperature, so consider if you want that.

Sugar — Coconut sugar and brown sugar are both acceptable. Coconut sugar yields a more caramel-like, less sweet profile; brown sugar gives a classic, moist banana-bread flavor.

Flour — The recipe supports either a regular all-purpose flour or a cup-for-cup gluten-free blend. If you choose gluten-free, make sure your blend contains a binder (xanthan gum or similar) for the best slice.

Baking soda — Works with the starter and acidic notes in banana to give lift. Make sure it’s fresh; expired baking soda won’t react as well.

Walnuts — Folded in for texture and nuttiness. Toasting the walnuts briefly before chopping will intensify their flavor, but this is optional.

Store, Freeze & Reheat

Room temperature: Wrapped tightly in plastic wrap or stored in an airtight container, the loaf will keep 2–3 days at room temperature.

Refrigerate: If your kitchen is warm, refrigerate the loaf wrapped for up to 5 days. Note that chilling can firm the crumb; bring slices to room temperature or warm gently before serving.

Freeze: Slice the cooled loaf and wrap individual slices in parchment and then foil or place them in a freezer-safe bag. Freeze for up to 3 months. Thaw slices on the counter or toast directly from frozen for a quick snack.

Reheat: Warm slices in a toaster oven or conventional oven at 300°F (150°C) for 6–10 minutes, or microwave a single slice for 15–25 seconds (watch timing to avoid drying out).

Troubleshooting Q&A

Q: My loaf sunk in the middle. A: Sinking usually happens if the batter was overmixed, the oven temperature fluctuated, or the loaf was slightly underbaked. Check that your oven is at the correct temperature and insert a toothpick at 50 minutes; if moist batter remains, give it more time.
Q: The crumb is gummy. A: This can be caused by underbaking, too much moisture, or cooling the loaf in the pan for too long. Remove the loaf from the pan after 10–15 minutes to let it finish setting on a wire rack.
Q: My batter felt thin. A: Bananas vary in moisture. If your bananas are exceptionally large or watery, you can reduce added water in other ingredients (this recipe has no extra water beyond the flax step) or add a tablespoon more flour to adjust consistency.
Q: It didn’t rise much. A: Make sure your baking soda is fresh and that your starter has some activity. A very inactive starter or old baking soda will reduce lift.
Q: Walnuts turned soggy. A: Toast walnuts lightly before folding them in if you want extra crunch. Do this on a dry skillet for a few minutes until aromatic, then cool and chop.

Save & Share

If you bake this loaf, let it cool completely and slice it to appreciate the crumb. Save the recipe by bookmarking this page or printing a copy to keep with your favorite kitchen notes. Share a photo with friends or on social media — tag a friend who keeps a sourdough starter or someone who always has overripe bananas on the counter.

I love seeing adaptations, so if you swap the walnuts for pecans, add chocolate chips, or use a rye-forward starter, tell me what you did and how it turned out. Happy baking — this one is cozy, simple, and reliably good.