Preheat oven to 350 degrees. Lightly butter one 9-by-5 inch loaf pan.
Mix flour, sugar, baking poweder, salt, baking soda, cinnamon, and nutmeg in a large bowl. In a medium bowl, whisk eggs, melted butter, yogurt, vanilla and zest together. Add banana to egg mixture, then fold to combine.
Spread batter in the prepared pan. bake until toothpick inserted in to the center comes out clean, about 55 minutes.
Cool 30 minutes in the pan on a rack, then turn out onto the rack to cool completely.