For crust: Combine flour, baking powder, sugar and salt in food processor. Add shortening and butter and pulse until coarse meal forms. Add ice water slowly, while using pulse. Blend until moist clumps form and add more water by the teaspooon if dough is a little dry. Be careful not to add too much water. Form dough into a ball and flatten into a disk. Wrap in plastic wrap and chill in refrigerator for 1 hour.

For streusel topping: Combine flour, sugar, cinnamon and salt in food processor. Drop butter in by pieces pulsing until mixture is crumbly. Cover and chill for at least 1 hour.

For berry filling: Preheat oven to 350F. Remove dough from refrigerator and press over bottom and up sides of a 12" cast iron skillet. Whisk sugar, flour and salt in medium bowl. Whisk sour cream and eggs in large bowl. Stir dry ingredients into sour cream mixture. Fold in berries. Spoon filling into crust and sprinkle with streusel.

1. Bake for roughly 1 1/2 hours or until top is puffed and golden and the centre is cooked through. Allow to cool for 30 minutes before serving.