In a large bowl, cream together shortening and 1 cup sugar until smooth. Beat in the egg, then stir in the cream and vanilla. Combine 3 1/2 cups flour, baking powder, baking soda and salt; stir into the creamed mixture. Cover and refrigerate dough for 2 hours, or until firm.
To make the filling: In a medium saucepan over medium heat, stir together 1/2 cup of sugar and 1 tablespoon flour. Mix in the raisins, walnuts and water. Cook until thickened, stirring constantly. Remove from heat and allow to cool.
Preheat oven to 350 degrees F (175 degrees C). Grease cookie sheets. On a floured surface, roll out dough to 1/4 inch thickness. Using a round cutter, cut out 48 circles 2 1/2 to 3 inches in diameter. Assemble the cookies by placing one onto the cookie sheet, place a teaspoon of filling in the center, then cover with another cookie. Press the edges together with a fork to seal. Repeat with remaining dough, spacing cookies 2 inches apart.
Bake for 12 to 15 minutes in the preheated oven, or until edges are golden brown. Remove from cookie sheets to cool on wire racks. CAUTION: Filling will be EXTREMELY HOT!