Mix flour, baking powder & salt together. Cut in butter to flour mixture until it resembles coarse meal. Then add apple cider vinegar and cold water. Mix into a ball and roll out. Prick crust so it does not bubble.
2Bake crust at 400 F degrees for about 15 minutes or until lightly golden. Cool.
3Filling: Combine all ingredients and cook until thick.
Spoon filling into cooled pie crust and cover with a meringue or whipped cream.