TO MAKE PASTRY:.
In medium bowl, combine flour, sugar, salt and baking powder. Cut in butter or margarine and shortening until mixture is crumbly. Add water, 2 tablespoons at a time, mixing with a fork. Add a little more water if necessary. Press mixture into 2 flat discs. Wrap in waxed paper and refrigerate for 30 minutes.
On lightly floured board, roll pastry discs to 1/16 inch. Cut into 5-inch circles. Roll scraps of dough and cut again. Line twelve 3 1/2-inch tart pans with pastry.
TO MAKE FILLING:.
Divide Walnuts equally between tart shells.
Beat together eggs, syrup, brown sugar, melted butter or margarine and vanilla until just blended. Pour maple syrup mixture over walnuts.
Bake in 425F oven for 20-25 minutes, or until pastry is golden and filling is soft set.
Let stand 15 minutes before removing from tart pans.
Serve warm or at room temperature, plain or with lightly sweetened cream.