Roll out the larger dough ball on a lightly floured surface into a circle about 12 inches in diameter.
Gently transfer dough by wrapping it round the rolling pin and unrolling it onto an 8-inch (20cm) pie plate. Line pie plate with the dough and trim pastry to ½ inch beyond pie plate.
Spoon prepared filling on the pastry lined pie plate.
Roll out the remaining dough ball. Cut pastry into ¾-inch (2 cm) strips.
Weave strips over filling to form the lattice crust. Press end of strips onto the edge of pie plate. Trim off excess pastry and crimp the edge with a fork.
If desired, cut out snowflakes from the dough trimmings using a cookie cutter.
Brush lattice crust with egg wash. Arrange snowflake cutouts on lattice crust decoratively. Brush egg wash on each of the snowflake cutouts.
Bake in a 350˚F (180°C) oven for 60 minutes or until crust is golden brown and filling is bubbly. Remove from oven and allow pie to cool slightly before serving.