Preheat oven to 350°. Grease and flour a 13-cup coffee cake pan or 2 9” cake pans, set aside. (I like to use non-stick baking spray with flour.)
Stir together flour, baking powder, cinnamon and salt. Set aside.
In a mixing bowl, beat sugar with softened butter until light and fluffy, about 5 minutes. Add eggs one at a time beating well after each addition. Mix in vanilla.
Alternate adding dry ingredients and milk to the butter sugar mixture, beating well after each addition. Mix in peaches.
Spoon batter in to prepared pan.
Bake in preheated oven 25 minutes.
Prepare Crumb Topping: Combine sugar, flour, and cinnamon in a small mixing bowl. Add butter and mix until mixture resembles wet sand.
After 25 minutes, sprinkle crumb topping on top of cake and bake for an addition 20 to 30 minutes, or until toothpick inserted in cake comes out clean.
Icing
Whisk together powdered sugar and milk to create a thin glaze.
Cool for 10 minutes before removing from pan. Drizzle icing on cake. Cool completely on a wire rack before serving.