Directions
1. Preheat oven to 400 F. In a large mixing bowl, combine sugar and flour.
2. Add eggs and beat with an electric mixer on medium-high speed until very thick and creamy, about 3 or 4 minutes.
3. Add vanilla, milk and orange zest and continue to mix on medium speed for 2 minutes.
4. Pour filling into prepared pie crust, set in baking tin.
5. Bake for 10 minutes. Reduce heat to 350 F and bake for another 15 to 25 minutes or until filling is almost set.