Prep the pan and oven. Heat oven to 350°F (175°C). Line a 9x5-inch loaf pan with parchment, letting it hang over the long sides for easy lifting. Lightly grease.

Brown the butter. In a small saucepan, melt butter over medium heat. Cook until it foams, then turns golden with brown bits and a nutty smell, 4–6 minutes. Transfer to a bowl to cool 5 minutes.

Mash the bananas. In a large bowl, mash bananas until mostly smooth with a few small lumps. Aim for about 1 1/3 cups.

Whisk in wet ingredients. Add brown sugar, eggs, tahini, vanilla, and yogurt. Whisk until well combined. Stir in the cooled brown butter.

Combine dry ingredients. In a separate bowl, whisk flour, baking soda, salt, cinnamon, and cardamom.

Bring it together. Add dry ingredients to the banana mixture. Fold gently with a spatula until a few streaks of flour remain. Do not overmix.

Add your flavor path. Fold in one set of mix-ins: espresso and chocolate, miso with maple and walnuts, or coconut with lime zest and juice. Keep folds minimal to preserve tenderness.

Top for crunch. Scrape batter into the pan. Sprinkle turbinado sugar and sesame seeds (or nuts) evenly over the top.

Bake. Bake 55–70 minutes, until a tester comes out with just a few moist crumbs. If top browns too fast, tent loosely with foil for the last 10–15 minutes.

Cool properly. Let loaf cool in the pan 15 minutes, then lift out and cool on a rack at least 1 hour before slicing. This sets the crumb and keeps slices clean.