Traditional Hamantaschen

Into a bowl sift together flour, baking powder, and salt. In another bowl with an electric mixer beat shortening, sugar, and egg at medium speed until light and fluffy. Add zest and juice and beat until incorporated. Add flour mixture, stirring, until a smooth dough is formed. Gather dough into a ball and flatten into a disk. Chill dough, wrapped in plastic wrap, at least 3 hours and up to 2 days.

Preheat oven to 375° F.

Halve dough. On a lightly floured surface roll out half of dough (keeping other half wrapped and chilled) 1/4 inch thick. With a 3-inch cutter cut out as many rounds as possible. Transfer rounds with a metal spatula to a large baking sheet, arranging about 1/2 inch apart. Reroll scraps and cut out more rounds. Put 1 teaspoon filling in center of each round and fold up edges to form triangular cookies resembling a tricornered hat, pinching corners together and leaving filling exposed. (Pinch dough tightly enough so seams are no longer visible and sides are taut enough to prevent cookies from leaking filling as they bake.)

Bake hamantaschen in middle of oven 20 minutes, or until pale golden. Cool hamantaschen on baking sheet 5 minutes and transfer to racks to cool completely. Make more hamantaschen with remaining dough and filling in same manner. Hamantaschen keep in an airtight container at room temperature 5 days.