1. Preheat the oven to 375 degrees F. For cookies, beat margarine, vanilla, salt, and sugar until well combined. Blend in flour, water, and chopped chocolate. Shape the dough into 1" balls. If dough is too crumbly, add a little more water.
2. Place the dough balls on an ungreased baking sheet and make a depression in the center of each ball with your thumb. Bake for 10-12 minutes. Cool completely before filling.
3. For filling, melt chocolate and shortening in a double boiler. Remove from heat and stir in vanilla, water, and corn syrup. Fill the cookies and let rest until filling cools and sets.
Source of recipe: Playing in the kitchen.