Preheat oven to 375 degrees F.
Sift dry ingredients together. With a pastry cutter, blend in the butter and shortening until the mixture resembles coarse meal. Add the ice water gradually until dough forms. Pat dough into a flat disk, wrap in plastic wrap and refrigerate for at least an hour.
Roll the dough 1/4-inch thick. With a cookie cutter, cut out ten 41/2-inch circles. Press the circles into 10 cups of a muffin tin. Put the muffin tin in the freezer for 20 minutes. Bake for 30 minutes, or until pastry is golden and set. Cool on a wire rack.
In a medium bowl, lightly beat together the egg, brown sugar, maple syrup, butter, vanilla and salt.
Divide the currants among the shells. Pour the mixture into the shells and bake until set, about 15 minutes. Let cool 5 minutes. Remove tarts from pan and cool on a wire rack.