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Okinawan Purple Sweet Potato Pie With Haupia Topping

The first time I saw an Okinawan sweet potato, I almost dismissed it. Its beige skin hid the treasure within, and it sat modestly among its more vibrant cousins at the farmer’s market. But my curiosity got the better of me, and once I roasted that first potato, I was forever changed. The intense purple hue and subtly sweet, almost floral flavor transported me back to childhood memories of my grandmother’s secret ingredient – a touch of something unexpected that elevated every dessert. Now, this pie is my way of sharing that same surprise and delight.

Recipe Overview

Prep Time: 1 hour
Cook Time: 1 hour
Total Time: Overnight (includes refrigeration)
Servings: 24
Yield: 1 9×13 inch pan
Dietary Type: Not specified, contains dairy, eggs, and gluten

Ingredients

Shortbread Crust

1 cup salted butter, softened
1 cup sugar
2 large eggs
3 cups flour
1 tablespoon vanilla extract
1/2 cup finely chopped macadamia nuts

Okinawan Sweet Potato Pie Filling

3 cups Okinawan sweet potatoes, cooked and mashed or whipped
3/4 cup unsalted butter, softened
2/3 cup sugar
2 eggs
1/2 cup whole milk (do not use skim)
1 1/2 teaspoons vanilla extract
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

Equipment Needed

9×13 inch baking pan
Mixing bowls
Electric mixer
Steamer or pot for boiling potatoes
Whisk
Thick-bottomed saucepan

Instructions

Prepare the Shortbread Crust: Preheat your oven to 300 degrees F (150 degrees C).
In a large mixing bowl, cream together the softened butter and sugar until light and fluffy. This is best done with an electric mixer.
Add the eggs one at a time, ensuring each is fully incorporated before adding the next. This prevents the mixture from curdling.
Gradually add the flour, mixing on low speed until just combined. Be careful not to overmix, as this can result in a tough crust.
Stir in the vanilla extract and finely chopped macadamia nuts.
Press the dough evenly onto the bottom of an ungreased 9×13 inch baking pan. Use your fingers or the back of a spoon to create a smooth, even layer.
Bake the crust for 30 minutes. The shortbread should be set but will not brown significantly. It is crucial not to overcook the crust at this stage.
Let the crust cool completely before adding the filling. This prevents the filling from soaking into the crust and making it soggy.
Prepare the Okinawan Sweet Potato Pie Filling: Preheat your oven to 350 degrees F (175 degrees C).
Peel and dice the Okinawan sweet potatoes into approximately 1-inch cubes.
Steam the diced sweet potatoes until they are tender and a deep, vibrant purple. Alternatively, you can boil them, but steaming preserves more of the color and flavor.
Once cooked, whip the potatoes until they are light and fluffy. For a smoother pie, use an electric mixer. If you prefer a chunkier texture, simply mash them to your desired consistency. Set aside to cool slightly.
In a separate large mixing bowl, cream together the softened unsalted butter and sugar until very fluffy. This creates a light and airy base for the filling.
Add the eggs one at a time, mixing until well incorporated after each addition.
Mix in the whole milk, vanilla extract, and salt. Ensure all ingredients are evenly distributed.
Gently fold the cooled sweet potatoes into the butter mixture until just combined. The batter should have a consistency similar to pancake batter.
Pour the sweet potato filling onto the cooled, baked shortbread crust, spreading it evenly.
Bake the pie for 30 minutes, or until the filling is set but still has a slight jiggle in the center.
Remove the pie from the oven and let it cool completely to room temperature.
Prepare the Haupia Topping: In a thick-bottomed saucepan, heat the coconut milk over medium heat until it is warm, but not boiling.
In a large mixing bowl, combine the sugar and cornstarch. This helps prevent lumps from forming in the topping.
Add the lukewarm water to the sugar and cornstarch mixture, and whisk until smooth.
Slowly add the cornstarch mixture to the warm coconut milk in the saucepan, whisking constantly to prevent lumps.
Continue whisking over medium heat until the mixture has thickened to a pudding-like consistency (about 5-7 minutes).
Let the Haupia topping cool slightly before pouring it evenly over the baked sweet potato pie layer.
Refrigerate the pie overnight to allow the Haupia topping to set completely and the flavors to meld.

Expert Tips & Tricks

Preventing a Soggy Crust: For an extra crispy crust, you can blind bake it before adding the filling. To do this, line the crust with parchment paper and fill it with pie weights or dried beans. Bake for 15 minutes, then remove the weights and bake for another 10 minutes.
Sweet Potato Consistency: The texture of your sweet potatoes will significantly impact the pie’s texture. For a smoother pie, use an electric mixer to whip the potatoes. For a more rustic pie, mash them by hand.
Haupia Troubleshooting: If your Haupia topping is lumpy, you can try passing it through a fine-mesh sieve to remove the lumps. Ensure that you whisk constantly while cooking the topping to prevent lumps from forming in the first place.
Macadamia Nut Alternatives: If you can’t find macadamia nuts, you can substitute them with other nuts like walnuts or pecans, or omit them entirely.

Serving & Storage Suggestions

Serve the Okinawan Purple Sweet Potato Pie chilled, straight from the refrigerator. To enhance the presentation, consider garnishing with toasted coconut flakes, a sprinkle of macadamia nuts, or a dusting of powdered sugar.

Leftover pie should be stored in an airtight container in the refrigerator for up to 3-4 days. While it’s best enjoyed cold, you can gently reheat individual slices in the microwave for a few seconds if desired. Freezing is not recommended, as the texture of the Haupia topping may change upon thawing.

Nutritional Information

(Estimated per serving, assuming 24 servings)

Nutrient	Amount per Serving	% Daily Value
Calories	413 kcal	N/A
Total Fat	21.5g	33%
Saturated Fat	13.8g	69%
Cholesterol	67.1mg	22%
Sodium	151.9mg	6%
Total Carbohydrate	52.3g	17%
Dietary Fiber	1.2g	4%
Sugars	34.5g	N/A
Protein	3.8g	7%

Variations & Substitutions

Gluten-Free Crust: Substitute the all-purpose flour in the shortbread crust with a gluten-free flour blend. You may need to add a binder, such as xanthan gum, to help hold the crust together.
Dairy-Free Filling: Replace the whole milk with coconut milk or another non-dairy milk alternative. You can also use a dairy-free butter substitute for the butter in the filling.
Vegan Option: Substitute both the milk and butter in the filling as described above. Replace the eggs with a flax egg (1 tablespoon ground flaxseed mixed with 3 tablespoons water, let sit for 5 minutes). Be aware that the texture may be slightly different.
Spice it Up: Add a pinch of cinnamon, nutmeg, or ginger to the sweet potato filling for a warmer, spicier flavor profile.

FAQs (Frequently Asked Questions)

Q: Can I use regular sweet potatoes instead of Okinawan sweet potatoes?
A: While you can, the flavor and vibrant purple color of the Okinawan sweet potato are what make this pie special. Regular sweet potatoes will result in a different flavor and appearance.

Q: Can I make the crust ahead of time?
A: Yes, you can bake the crust a day or two in advance and store it in an airtight container at room temperature.

Q: Why do I need to refrigerate the pie overnight?
A: Refrigerating the pie allows the Haupia topping to set completely and the flavors to meld together, resulting in a more cohesive and delicious dessert.

Q: My Haupia topping is too thick/thin. What did I do wrong?
A: The consistency of the Haupia topping depends on the ratio of cornstarch to liquid and the cooking time. If it’s too thick, whisk in a little more warm water. If it’s too thin, cook it a little longer, whisking constantly.

Q: Can I reduce the amount of sugar in the recipe?
A: You can reduce the sugar slightly, but be mindful that it affects the texture and stability of both the filling and the Haupia topping. Start by reducing the sugar by 1/4 cup and adjust to your taste.

Final Thoughts

This Okinawan Purple Sweet Potato Pie with Haupia Topping is more than just a dessert; it’s a celebration of unexpected flavors and textures. The earthy sweetness of the purple sweet potato combined with the creamy coconut Haupia creates a truly unforgettable experience. Don’t be afraid to experiment with variations to make it your own, and most importantly, share it with loved ones and watch their faces light up with delight. I encourage you to try this recipe and let me know what you think! This pie pairs perfectly with a cup of strong Kona coffee or a light, fruity white wine.

Okinawan Purple Sweet Potato Pie With Haupia Topping Recipe