Filling: Drain ricotta well in strainer. Beat ricotta and vanilla until smooth in mixer or food processor. Stir in powdered sugar until well mixed. Add citron and chocolate chips. Store in refrigerator.
Shells: Using a wire whisk, mix together flour, sugar, cinnamon, and salt. Cut shortening into dry ingredients like pie crust. Mix together eggs, vinegar and water. Add to dry ingredients to make a dough. Roll out all of the dough very thin (1/16" or less-must be thin!) Use 3" round cookie cutter and cut out as many as you can all at one time. If dough gets thicker after cutting out rounds, take cannoli tube and roll each one thinner before you wrap it around tube. Wrap and seal with beaten egg white, pressing dough down to seal good or it will come apart in hot oil. Wrap all of your tubes before frying. Heat 3 to 4 inches of oil to 350 degrees and fry only 2 to 3 at one time for 1 minute or till golden brown. Remove from oil with tongs and holding tube with pliers, pull off shell using tongs to hold the shell. Let drain on paper towels.Use a pastry bag to put ricotta into shells. Do this right before you are ready to serve