Sift together flour, baking powder, and salt.
Cut in butter until particles are the size of small peas.
Sprinkle 3 to 4 tablespoons beaten egg over flour mixture, stirring with fork to form a dough.
Roll out on floured surface to slightly less than ⅛ inch thickness.
Cut into 3-inch rounds.
Fit into small paper baking cups (tea size cups).
Place on baking sheets.
Chocolate Filling: Melt semisweet chocolate pieces in top of double boiler over boiling water.
Stir in sugar, milk, butter, and vanilla; remove from heat.
Blend in 1 beaten egg. Place a scant tablespoonful of filling in each pastry shell.
Top with a pecan half.
Bake in moderate oven (350 degrees) 15 to 20 minutes.