Preheat oven to 350 degrees. Grease a 9×13 inch baking dish.
Combine the first 5 ingredients in a medium sized bowl. Beat at medium speed until everything is well blended. Pat mixture into the prepared 9×13 inch baking dish. Bake for 20 minutes or until golden brown.
Combine 2 cups sugar and cornstarch. Add eggs, lemon rind, lemon juice, grated ginger and butter; beat well. Add candied ginger. Pour mixture over the warm crust.
Return the dish to the oven and bake at 350 degrees for 20-25 minutes or until set. Cool it down and put in the refrigerator to chill completely. Sift the powdered sugar on top before serving!