Trust me - they taste better than they look! (I think I need fresh baking powder).
My first clue should have been the recipe name: "Big Beautiful Muffins"
I used a cupcake tin. I should have used a muffin tin.

3 cups all-purpose flour
1 cup sugar
1 tbsp baking powder
1/2 tsp baking soda
1/2 tsp salt
1 1/2 cups lowfat plain yogurt
2 large eggs
8 tbsp (1 stick) unsalted butter, melted and cooled (oops...forgot to cool it!)

1. Adjust an oven rack to the middle position and heat the oven to 375 degrees. Generously coat a 12-cup muffin tin with vegetable oil spray.
2. Mix the flour, sugar, baking powder, baking soda, and salt together in a large bowl. Whisk the yogurt and eggs together in a medium bowl. Gently fold the yogurt-egg mixture into the flour mixture with a rubber spatula until just combined. Fold in the melted butter.
3. Use a large ice-cream scoop or measuring cup to divide the batter evenly among the muffin cups. Bake until golden and a toothpick inserted into the center of a muffin comes out with just a few crumbs attached, 25-30 minutes. (These took about 20 minutes, since they were smaller.)
4. Let the muffins cool in the pan for 5 minutes, then flip out onto a wire rack and let cool for 10 minutes before serving.

Variation: Lemon-Blueberry Muffins
Add 1 tsp grated lemon zest to the yogurt-egg mixture and fold 1 1/2 cups fresh or frozen blueberries that have been tossed in 1 tbsp flour into the finished batter. If using frozen blueberries, rinse them in a strainer until the water runs clear, then drain on paper towels and pat dry before stirring (unfloured) into the batter.

Makes 18 cupcake-sized or 12 larger muffins
From The America's Test Kitchen Family cookbook