Heat oven to 400°. Line muffin cups with paper liners.
In large bowl, whisk together dry ingredients.
In separate bowl, combine oil, eggs, milk, and vanilla until well incorporated.
Pour wet ingredients into dry ingredients. Stir until just combined (do not over mix). Fold in peaches.
Spoon batter into muffin cups (the batter will come to the tops of the paper liners). Lightly sprinkle sugar over tops.
Bake for 15-20 minutes until tops are golden and spring back when touched. Transfer to wire rack to cool completely.