1. In a large bowl combine the flour, granulated sugar, baking powder ,cinnamon and salt, stir with a fork to combine.
2. In a medium size bowl add the melted butter, milk and egg. Whisk to thoroughly combine.
3. Place the peeled,pitted and cubed peaches in a medium size bowl, toss with 1 teaspoon of lemon juice. Set aside.
4. Add the milk/egg mixture to the flour mixture and fold together till moist. Add the peaches to the batter and fold till just incorporated.
5. Fill the muffin tins or paper liners 3/4 full, sprinkle batter with topping. Bake at 400 degrees for 20 - 25 minutes, testing with a toothpick for doneness. Let cool slightly and remove from muffin tins.