1) Preheat oven to 350 degrees F. In a large mixing bowl, stir together yogurt, sugar, and eggs. Then stir in flour, baking powder, salt, and melted butter. Batter will be fairly thick.
2) Fold in blueberries and scrape batter into a 9×5 loaf pan that has been greased or lightly buttered.
3) Bake cake for 45-50 minutes, rotating once halfway through, until a tester comes out clean.
4) Allow cake to cool for a few minutes and then remove from the pan and serve either warm or at room temperature.
Leftovers keep fine for a few days wrapped tightly in plastic wrap.