In a med-sized metal bowl, combine flour, salt and baking powder. Add butter and cut into flour with pastry cutter until crumbs form and it resembles a course meal. Sprinkle with vinegar and water and knead gently until dough forms. Do not over-mix. Wrap dough in plastic wrap and chill at least 2 hours or overnight.
Processor method: Combine flour, salt and baking powder with cold butter, pulse briefly and add vinegar and water until combined (approx. 15-20 sec). Do not over-mix, or dough will be tough. Chill, as above.
Preheat oven to 375º. Roll out dough to form a 13” circle (rough edges add character). Place into a 10” springform pan and press 1½” up the sides of the pan. Set aside.
Baker’s Tip: Roll out dough on floured plastic wrap for easy transfer to pan.
Wash lemon and remove ends, quarter and remove seeds, but do not remove the rind. Add all ingredients to blender and blend well to incorporate until liquefied. Pour into unbaked tart shell. Bake at 375º for 10 min, then lower temp. to 325º and bake 30-40 more min, or until knife comes out clean. Top with fresh raspberries and a light dusting of powdered sugar.