Okinawan Purple Sweet Potato Pie With Haupia Topping

The Okinawan sweet potato is a very special potato. It doesn't look like much from the outside (<a href="http://labofedibles.wordpress.com/2007/12/13/the-ugly-duckling-okinawan-purple-sweet-potato/">This site</a> calls it the ugly ducking of potatoes), but it is one beautiful and delicious spud! <p> This pie is a mixture of recipes from <a href="http://onokinegrindz.typepad.com/ono_kine_grindz/2004/10/okinawan_sweet_.html">Reid at Ono Kine Grindz </a> and my family's special shortbread recipe. <p> I would not use any other potato for this recipe. It IS labor intensive, but the pay off is so worth it! This should be a smooth, rich, mouth-watering treat. People always ask me to make this for them.<p> Cooking time does not include overnight refrigeration.

• Ready In: 2 hrs 30 mins
• Serves: 24
• Yields: 1 9X13 pan

Ingredients

• Shortbread Crust

• 1  cup salted butter
• 1  cup sugar
• 2  large eggs
• 3  cups flour
• 1  tablespoon vanilla
• 1⁄2 cup  finely chopped  macadamia nuts

• Okinawan Sweet Potato Pie Filling

• 3  cups  okinawan sweet potatoes
• 3⁄4 cup unsalted butter
• 2⁄3 cup sugar
• 2  eggs
• 1⁄2 cup  whole milk (do not use skim)
• 1 1⁄2 teaspoons vanilla
• 1⁄2 teaspoon salt

• Haupia Topping

• 1⁄2 cup sugar
• 1⁄2 cup cornstarch
• 1 1⁄4 cups  lukewarm water
• 2 (12 ounce) cans coconut milk

Directions

1. To Make the Shortbread Crust.
2. Preheat oven to 300 degrees F.
3. Cream the butter and sugar together.
4. Add the eggs one at a time, making sure that the eggs are well incorporated after each addition.
5. Add flour slowly.
6. Add vanilla and chopped macadamia nuts.
7. Press the dough down onto an ungreased 9 X 13 pan.
8. Bake for 30 minutes. Shortbread will not brown. DO NOT OVERCOOK!
9. Let cool.
10. Start on the Okinawan Sweet Potato Pie Filling:.
11. Preheat the oven to 350 degrees F.
12. Peel and dice (about 1-inch cubes) the Okinawan Sweet Potato and steam until tender and dark purple.
13. Whip the potatoes until fluffy. If you prefer a chunkier style of pie, mash the potatoes to your preference. Set aside to allow to cool.
14. In a large mixing bowl, cream together butter and sugar until very fluffy.
15. Add in eggs one at a time and mix until well incorporated.
16. Mix in milk, vanilla and salt.
17. Fold the potatoes into the butter mixture. It should have the consistency of pancake batter.
18. Pour onto the baked crust and bake for 30 minutes.
19. Remove from oven and let it cool down to room temperature.
20. To make the Haupia topping.
21. In a thick-bottomed pot, heat the coconut milk until it is warm.
22. In a large mixing bowl, combine sugar and cornstarch.
23. Add water to the bowl.
24. Slowly add the cornstarch mixture to the pot, whisking constantly until the mixture has thickened. (about 5-7 minutes).
25. Let the mixture cool slightly, and pour it over the baked sweet potato pie layer.
26. Refrigerate overnight.