Prep the pan and oven: Preheat the oven to 350°F (175°C). Line a 9x5-inch loaf pan with parchment, leaving overhang for easy lifting. Lightly grease the sides.

Mash the bananas: In a large bowl, mash the bananas until mostly smooth with a few small lumps. You want about 1 1/3 to 1 1/2 cups.

Whisk wet ingredients: Add eggs, oil, yogurt, brown sugar, and vanilla. Whisk until well combined and glossy.

Combine dry ingredients: In a separate bowl, whisk the gluten-free flour, baking soda, baking powder, salt, and cinnamon. This prevents clumps and ensures even lift.

Bring it together: Add the dry ingredients to the wet. Stir gently with a spatula until just combined. A few streaks of flour are okay. Do not overmix.

Add chocolate chips: Fold in the chocolate chips, reserving a tablespoon to sprinkle on top if you like.

Fill the pan: Scrape the batter into the prepared pan. Smooth the top, then sprinkle with the reserved chips and turbinado sugar for a bakery-style finish.

Bake: Place on the center rack and bake for 55–70 minutes. Start checking at 55 minutes. The loaf is done when a toothpick inserted in the center comes out with a few moist crumbs, not wet batter.

Cool properly: Let the loaf cool in the pan for 15 minutes, then lift it out using the parchment and transfer to a wire rack. Cool at least 1 hour before slicing for clean cuts.

Slice and serve: Use a sharp serrated knife. For warm, melty chocolate, serve slightly warm. For neater slices, let it cool completely.