Preheat oven to 350 degrees. Mix sugar, cornstarch, salt, and cinnamon, and sprinkle over blueberries in a bowl. Set aside.Cut butter into 1/2-inch cubes and freeze. Combine flour and salt in a large mixing bowl. Add frozen butter and shortening. Toss together in a food processor and pulse until combined. Pour water through the top until combined a little at a time. You may not need all of the water. Divide dough in half. Roll out one piece for the bottom crust. Fill with blueberry filling. Roll out second dough. Use an Exacto Knife to cut out 2 eyes and a mouth. Cover the blueberry filling with the top dough. Crimp the edges to seal. Cut off the excess dough hanging off. Beat the egg and water. Brush the egg wash all over the top crust. Bake in a 350 degree oven for an hour or until browned. Cool on a wire rack.