Preheat the oven to 180 C (350F). Grease a 9×5 inch loaf pan with non stick spray, then line with parchment paper with some overhang so you can lift the finished cake out easily.
Whisk the flour, baking powder, and salt in a bowl.
In a large bowl, combine the one cup of sugar with the orange zest, rubbing the orange zest into the sugar with your fingertips until the sugar is moistened and pale orange. Whisk in the yogurt or sour cream, eggs, and orange juice until well combined.
Use a spatula and add the wet ingredients to the flour mixture, stirring until just combined. Fold in the melted butter until just combined, then fold in the chocolate chips/chunks. Pour the batter into the prepared loaf pan, smoothing out the top.
Bake for 45-50 minutes or until light golden brown and toothpick inserted in the center comes out clean. Cool before topping with glaze.