Preheat and prepare. Set your oven to 190°C (170°C fan). Line a 12-hole muffin tin with paper cases. The anticipation begins now, as the oven warms and you gather your tools.

Mash the bananas. In a large bowl, peel and add the bananas. Use a fork to mash them until they are a chunky, lumpy purée. You want some texture remaining – a few pea-sized pieces are perfect. You should hear the soft squelch of them breaking down. Aim for a consistency that looks like a thick, sludgy porridge.

Mix the wet ingredients. To the mashed banana, add the peanut butter, oil, brown sugar, eggs, and vanilla extract. Stir with a wooden spoon or spatula until everything is combined. The mixture will look a little speckled and glossy. It should smell intensely of peanut butter and sweet banana.

Combine the dry ingredients. In a separate, smaller bowl, whisk together the flour, bicarbonate of soda, baking powder, and salt. This ensures the raising agents are evenly distributed, so you don’t get one lopsided muffin that rises while its neighbour stays flat. The flour should look light and aerated.

Fold the batter together. Tip the dry ingredients into the wet mixture. Using a gentle hand, fold everything together with a spatula. Stop as soon as no streaks of flour remain. The batter will be thick, shaggy, and quite stiff – do not overmix, or the muffins will be tough. If you are adding chocolate chips, fold them in now.

Fill the cases. Divide the batter evenly among the 12 paper cases. They should be almost full – about three-quarters full to the top. For a bakery-style dome, use a small ice cream scoop or two spoons to mound the batter slightly higher in the centre. If using, scatter a few chopped peanuts on top of each muffin.

Bake until golden and fragrant. Place the tin in the centre of the oven and bake for 18–22 minutes. The muffins are ready when they are domed, a deep golden brown, and a skewer inserted into the centre of one comes out clean or with a few moist crumbs. Your kitchen will be thick with the scent of toasted peanuts and caramelised banana. The tops should spring back when lightly pressed.

Cool completely. Let the muffins rest in the tin for 5 minutes – this allows them to set and makes them easier to handle. Then, transfer them to a wire cooling rack. The sound of them gently releasing from the paper is a small satisfaction. Let them cool completely before storing, as the steam can make the tops soggy if they are sealed too early.