Preheat oven to 375 D.
Prepare your favorite dough, using half a recipe for a double-crust pie.
To roll out: Roll the dough 1/16 thick on a lightly floured surface. With a cookie cutter, cut out 12x3”-inch circles. Roll each circle gently out slightly thinner to allow for slight shrinkage while baking. Press the circles into a muffin tin for 12 or a mini-muffin tin for 24. Put the muffin tin in the freezer for 20 minutes. Repeat with other half of dough.
Meanwhile, in a medium bowl, lightly beat together the egg, brown sugar, maple syrup, melted butter, vanilla and salt. Pour into a small measuring cup with spout for easy pouring.
Sprinkle a few blueberries into chilled shells .Pour filling over blueberries filling just until pastry’sedge and bake at 375 for 5 minutes then reduce temperature to 350 and cook for another 15 minutes or until set and bottoms of pastry are just turning golden. Let cool 5 minutes. Remove tarts from pan and cool on a wire rack