Preheat the oven to 350ºF (180ºC).
Line 12 regular muffin tins with paper liners or butter/spray the pans.
In a large bowl, mix the dry ingredients: sifted flour, baking powder, salt and sugar. Mix to combine.
Whisk eggs, milk, oil, and vanilla in a medium bowl. Do not beat but mix well until no streaks of egg whites remain.
Add the wet ingredients at once to the bowl with the dry ingredients.
Stir to integrate, but do NOT overmix. It will be lumpy, and that is fine. I use a rubber spatula.
Divide evenly among the muffin cups or muffin liners.
Top with peach pieces. Be careful not to overflow the paper cups from too many chunks.
Sprinkle lightly with extra sugar.
Bake for 25 minutes, until the top is cracked, golden brown, and a cake tester or toothpick inserted in the center comes out clean. Don't overbake.
Let cool on a wire rack.
They are best eaten the day they are made, but you can keep them for a day at room temperature covered or wrapped.
Store leftovers, covered in plastic wrap or an airtight container, in the refrigerator for a few days or frozen for a month.