Preheat oven to 350 degrees.
Cook the cranberries for 2-3 minutes with half the sugar.
Cook the strawberries with the other half cup of sugar. Add 1 tablespoon of cornstarch and the raspberries.
Take out a half cup of the juice from the berry mixture and mix with remaining 1/2 tablespoon of cornstarch.
Stir into the fruit mixture. Place into oval baking dish.
Combine filling ingredients until crumbly.
Sprinkle over berries. Bake until golden brown for 20 to 25 minutes.