¾ cup plain yogurt
¾ cup whole milk
1 cup polenta
1 cup all purpose flour
1 ½ teaspoons baking powder
1 teaspoon kosher salt
2 tablespoons sugar, plus more for sprinkling
1 pound stone fruit, pitted, peeled, and diced
Preheat your oven to 375°F and grease a muffin tin well with butter or olive oil. Alternatively, cut two squares of parchment paper and overlap them on the diagonal, pushing it into the tin to form makeshift cups.
In a large bowl, whisk together the yogurt, milk, and egg.
In a small bowl, combine the polenta, flour, baking powder, salt, and sugar. With a silicon spatula, fold the dry ingredients into the wet ingredients gradually until well combined. Fold in two-thirds of the fruit.
Pour the batter into the tin and top the muffins with the remaining fruit and a sprinkle of sugar. Bake until the tops are golden brown and a toothpick inserted into the middle of the muffin comes out clean, about 30 minutes. Let cool in the pan for 5 minutes, then transfer to a cooling rack.