Grease and flour the bottom of a 9x5-inch loaf pan. Set the oven rack to lower middle position and heat oven to 375°F.
In a large bowl, whisk together flour, sugar, baking soda and salt; set aside.
2 cups all-purpose flour, ¾ cup granulated sugar, ¾ teaspoon baking soda, 1 teaspoon kosher salt
In a medium mixing bowl, mash together the bananas, yogurt, melted butter, vanilla and orange zest.
3 very ripe bananas, ¼ cup plain yogurt, 6 tablespoons unsalted butter, 1 teaspoon pure vanilla extract, 2 tablespoons orange zest
Lightly fold the mashed banana mixture and chocolate chips into the flour mixture with a rubber spatula. Mix the batter just until combined – it should be lumpy and thick.
1 cup semisweet chocolate chips
Transfer the batter to the prepared pan, smooth out the top and, if desired, arrange banana slices on top.
Bake 55-60 minutes, or until bread is golden brown and toothpick inserted in the middle comes out clean.
Transfer bread to a cooling rack and cool in the pan 5 minutes. After 5 minutes, turn bread out of the pan, turn right side up. Serve warm or at room temperature.