Preheat oven to 400 degrees F. Lightly grease 24 (2 3/4 x 1 3/8 inch) muffin cups. Place the peaches in a bowl and cover with 1/2 cup of the sugar. Mix thoroughly. Allow the peaches to sit tor 1 hour. Using an electric mixer fitted with a paddle, cream the butter and remaining 3/4 cup of sugar untilsmooth and pale in color, about 3 minutes. Add the eggsk, one at a time, and beat until fluffy, about 2 minutes. In a mixing bowl combine 3 1/2 cups of the flour, baking powder, and salt. Remnove the bowl from the mixer and alternately fold in the milk and flour mixture, being careful not to over mix. Fold in the peaches. Spoon 1/4 cup of the filling into each prepared muffin cup. In a small bowl, comine the remaining flour, brown sugar, pecans and cinnamon. Mix well. Add d the butter. Using your hands, mix until the mixture resembles coarse crumb like mixture. Wprinkle 1 tablespoon of the crumb mixture over each muffin cup. Place in the oven and bake for about 15 to 20 minutes or until golden brown. Serve warm with butter.