Step 1
To Make Filling: Combine ricotta cheese 1 1/4 cups white sugar and 2 teaspoons vanilla until smooth and creamy. Stir in candied citron and semi-sweet chocolate pieces. Refrigerate to chill.
Step 2
To Make Shells: Sift together into a bowl 3 cups flour 1/4 cup sugar 1 teaspoon cinnamon and 1/4 teaspoon salt. Cut in the shortening with a pastry blender until pieces are the size of small peas. Stir in 2 beaten eggs. Blend in the white vinegar and the cold water one tablespoon at a time.
Step 3
Turn dough onto lightly floured surface and knead until smooth and elastic. Wrap in waxed paper and chill in refrigerator for half an hour.
Step 4
From cardboard cut an oval pattern measuring 6 x 4 1/2 inches. Roll chilled dough 1/8 inch thick on floured surface. Using the cardboard pattern and a pastry cutter cut ovals from dough. Wrap dough ovals loosely around tubes just lapping over opposite edges. Seal edges by brushing with the slightly beaten egg white.
Step 5
Set out a deep saucepan 1/2 to 2/3 full of vegetable oil or shortening and heat to 360 degrees F (180 degrees C). Fry only as many cannoli shells as will float uncrowded one layer deep. Fry about 8 minutes or until golden. Turn occasionally while frying.
Step 6
Drain off excess fat before removing to absorbent paper. Cool slightly. Remove tubes. Cool shells completely.
Step 7
When ready to serve fill with chilled ricotta filling. Sprinkle ends of cannoli with chopped pistachio nuts and dust shells with confectioners' sugar. Keep cannoli filling refrigerated.