230gripe bananaAbout 2 medium bananas; weigh after peeling and mash with a fork.
120gunsalted butterSoftened at room temperature, not melted.
200ggranulated sugar
2eggsUse large eggs.
1tspvanilla extract
120gplain milk kefirUse milk kefir without draining off the whey.
180gall-purpose flour
1tspbaking sodaFood-grade.
1pinchsalt
You will need
Oven
23 × 13 cm loaf tin
Baking paper
Foil
Mixing bowls
Electric hand mixer
Fork and spatula
Kitchen scale and measuring spoons
Measuring jug
Skewer
Instructions
Preheat the oven to 175°C (350°F), with the rack in the middle.
Line the loaf tin with baking paper.
Stir the flour, baking soda and salt together in a bowl.
Beat the softened butter and sugar together until pale and fluffy.
Beat in the eggs one at a time, mixing well after each addition.
Mix in the mashed banana, kefir and vanilla until combined.
Gently fold in the flour mixture with a spatula, stopping when no dry flour remains.
Pour the batter into the lined tin.
Bake for 55–60 minutes. If the top darkens too quickly, cover it loosely with foil. Check the centre with a skewer. If it comes out with wet batter, keep baking until the skewer is clean or carries only a few moist crumbs.
Cool in the tin for 30 minutes, then lift the loaf out using the baking paper and slice.
Storage and safety
Let the loaf cool completely, then wrap well and refrigerate for up to 3 days. For longer storage, wrap slices individually and freeze. Do not taste the raw batter: it contains uncooked eggs and flour.