Preheat oven to 325.
Mix together flour, baking powder and salt.
Dust blueberries with flour.
Cream together butter and sugar.
Add eggs one at a time, mixing after each egg.
Add vanilla, mix well. Add sour cream and mix till well combined.
Add dry ingredients and mix well.
Fold in blueberries and peaches.
Spray loaf pan with cooking spray. Pour in batter.
Bake 1 hour and 20 minutes.
Cool slightly, brush with butter and sprinkle with decorative sugar.
Once cooled a little, run knife around edge and flip onto cooling rack.