Instructions

  1. Preheat oven to 400.
  2. Filling: In a large bowl, combine rhubarb, strawberries and frozen blueberries.
  3. Sprinkle with sugar, splenda, cornstarch, cinnamon and nutmeg, if using. Stir to combine well.
  4. In a separate bowl, stir sour cream and egg whites until combined. Fold into filling mixture and set aside.
  5. Prepare crust.
  6. Topping: Stir together oats, brown sugar, flour and orange zest, if using. Cut in butter with pastry cutter until you have course crumbs. Then sprinkle 1 tablespoon cold water and used your pastry cutter to distribute - you should still have course crumbs.
  7. Pour filling mixture into pie crust.
  8. Sprinkle crumble topping over filling.
  9. If desired, cover edges of crust with foil
  10. Bake at 400 for 15 minutes. Then reduce heat to 350 for another 35-40 minutes, until topping is golden.
  11. Cool on wire rack completely before cutting. Since this is a sour cream pie, you'll need to store leftovers in refrigerator.