Preheat your oven to 350°F (175°C). Grease a loaf pan or line it with parchment. Yes, this is the moment you pretend you’re hosting a bake-off.

In a large bowl, mash the bananas until mostly smooth. A few chunky bits are perfectly fine—character is allowed here.

Whisk in melted butter (or oil), sugar, egg, and vanilla. Stir until everything looks glossy and coordinated.

In a separate bowl, whisk together flour, baking soda, salt, and optional cinnamon. Dry ingredients meet wet ingredients in a gentle fold—do not overmix.

Fold in blueberries carefully, so they don’t all sink to the bottom or burst like tiny blueberry confetti.

Pour the batter into the prepared loaf pan. Give the pan a gentle tap to settle the batter and even out the top.

Bake 50–60 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. If the top browns too quickly, cover loosely with foil for the last 10 minutes.

Let cool in the pan for about 10 minutes, then transfer to a rack. Slice once it’s mostly cooled, or you’ll burn your tongue and your dignity.