In a bowl, combine flour, baking powder and salt; set aside. Combine sour cream and egg; mix well. Stir into dry ingredients just until moistened. Turn onto a lightly floured surface; knead gently 4 to 5 times. Roll to 1 cm thickness; cut with a 2- 1 cm biscuit cutter. Place on a greased baking sheet. Bake at 220ºC for 10 to dozen minutes or until lightly browned. Meanwhile in a blender or processor, process ham until finely minced. Add butter and continue processing until well mixed. Spread over warm biscuits.