Preheat your oven to 175°C (350°F). Grease or line a 9×5” (23×13 cm) loaf pan with parchment paper.
In a small bowl, mix the baking soda (5g) into your sourdough starter (120g) and let it sit for a few minutes while you prepare the rest of the ingredients. This helps activate the baking soda and gives a lighter texture to the bread.
120 g sourdough starter, 5 g baking soda
In a large mixing bowl, mash the ripe bananas (250g) until smooth. Add the eggs (100g), brown sugar (100g), melted butter (60g), sour cream (60g), vanilla extract (5g), and almond extract (2.5g). Whisk until well combined.
250 g ripe bananas, 100 g eggs, 100 g brown sugar, 60 g melted butter or coconut oil, 60 g sour cream, 5 g vanilla extract, 2.5 g almond extract
Add the sourdough starter and baking soda mixture to the wet ingredients and stir gently to combine.
Add the all-purpose flour (125g), almond flour (50g), and salt (3g). Stir until just combined—do not overmix.
125 g all-purpose flour, 70 g almond flour, 3 g salt
Fold in the sliced almonds (30–40g)(optional).
30 g sliced almonds
Pour the batter into the prepared loaf pan and smooth the top. (Optional: sprinkle with extra sliced almonds.)
Bake for 50–60 minutes, or until a toothpick inserted into the center comes out clean or with just a few moist crumbs.
Let the banana bread cool in the pan for 10–15 minutes, then transfer to a wire rack to cool completely before slicing.