Preheat your oven to 350°F (175°C)
In your stand mixer, whip room temperature butter and both sugars until whipped and fluffy
Add the eggs, sour cream, and vanilla, and whip again until smooth and creamy
In another bowl, whisk together the flour, salt, and baking powder
Gently fold the dry mix into the wet mix, mixing just enough to combine
Slowly pour in the milk while mixing on low until you have a thick batter
Fold in the blueberries and peaches by hand without smashing
Divide the batter evenly into a lined muffin tin and sprinkle turbinado sugar on top
Bake for about 30 minutes until golden or a toothpick comes out clean
Cool slightly on a wire rack
