Okinawan Sweet Potato Haupia Pie with Whipped Cream

Quick Recipe Version (TL;DR)

• Yield: 10 slices (1 x 9-inch pie)
• Prep Time: 30 minutes
• Cook Time: 1 hour 30 minutes
• Total Time: 6 hours (includes chilling)

Quick Ingredients

• Crust: 1 1/4 cups all-purpose flour, 1 tbsp sugar, 1/2 tsp salt, 10 tbsp cold unsalted butter, 3–4 tbsp ice water
• Sweet potato layer: 1 1/2 lb Okinawan sweet potatoes, 1 cup evaporated milk, 2 eggs, 1/2 cup sugar, 2 tbsp cornstarch, 2 tbsp melted butter, 1 tsp vanilla, 1 tbsp lemon juice, 1/4 tsp salt
• Haupia: 1 can (13.5 oz) full-fat coconut milk + 1/3 cup water, 1/2 cup sugar, 1/3 cup cornstarch, 1/4 tsp salt, 1/2 tsp vanilla
• Topping: 1 cup heavy cream, 2 tbsp powdered sugar, 1/2 tsp vanilla, toasted coconut flakes

Do This

• 1. Make dough: Cut butter into flour, sugar, salt; add ice water. Chill 30 minutes, roll into a 9-inch plate.
• 2. Blind-bake at 375°F: Line with parchment, fill with pie weights. Bake 20 minutes; remove weights and bake 10–12 minutes more until golden. Cool slightly. Reduce oven to 350°F.
• 3. Steam potatoes 15–20 minutes until tender; mash smooth and cool 5 minutes.
• 4. Whisk in evaporated milk, sugar, cornstarch, melted butter, vanilla, lemon juice, salt, then eggs. Pour into crust; bake at 350°F for 30–35 minutes until just set. Cool 30 minutes.
• 5. Cook haupia: Whisk coconut milk + water, sugar, cornstarch, salt over medium heat until thick and glossy, 5–7 minutes. Off heat, stir in vanilla.
• 6. Pour haupia over warm pie. Chill uncovered 30 minutes, then cover and chill 3 1/2–4 hours.
• 7. Whip cream with sugar and vanilla to soft peaks. Top pie; garnish with toasted coconut. Slice and serve cold.

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Why You’ll Love This Recipe

• Striking layers: vivid purple sweet potato custard topped with snowy, silky coconut haupia.
• Balanced flavor: earthy, naturally sweet potatoes meet cool, creamy coconut.
• Make-ahead friendly: chill until set for perfect, clean slices.
• Party showstopper: familiar pie format with unmistakable island flair.

Grocery List

• Produce: 1 1/2 lb Okinawan (purple) sweet potatoes, 1 lemon
• Dairy: Unsalted butter, evaporated milk, eggs, heavy cream
• Pantry: All-purpose flour, granulated sugar, powdered sugar, cornstarch, canned full-fat coconut milk, vanilla extract, fine salt, untoasted coconut flakes (for garnish)

Full Ingredients

Buttery Pie Crust

• 1 1/4 cups (150 g) all-purpose flour
• 1 tbsp (12 g) granulated sugar
• 1/2 tsp fine salt
• 10 tbsp (140 g) unsalted butter, very cold, cut in cubes
• 3–4 tbsp (45–60 ml) ice water

Purple Sweet-Potato Custard Layer

• 1 1/2 lb (680 g) Okinawan sweet potatoes, peeled and cubed
• 1 cup (240 ml) evaporated milk
• 2 large eggs
• 1/2 cup (100 g) granulated sugar
• 2 tbsp (16 g) cornstarch
• 2 tbsp (28 g) unsalted butter, melted and slightly cooled
• 1 tsp vanilla extract
• 1 tbsp fresh lemon juice (color stabilizer)
• 1/4 tsp fine salt
• Optional: 1/4 tsp ground cinnamon

Coconut Haupia Layer

• 1 can (13.5 oz / 400 ml) full-fat coconut milk
• 1/3 cup (80 ml) water (to bring total liquid to ~2 cups)
• 1/2 cup (100 g) granulated sugar
• 1/3 cup (40 g) cornstarch
• 1/4 tsp fine salt
• 1/2 tsp vanilla extract

Topping & Garnish

• 1 cup (240 ml) heavy cream, very cold
• 2 tbsp (16 g) powdered sugar
• 1/2 tsp vanilla extract
• 2–3 tbsp toasted coconut flakes, for garnish (optional)
• Optional: finely grated lime zest, for a bright finish

Step-by-Step Instructions

Step 1: Make and chill the buttery crust

In a bowl, whisk the flour, sugar, and salt. Cut in the cold butter with a pastry cutter or rub with fingertips until pea-sized bits remain. Sprinkle in ice water, 1 tablespoon at a time, tossing just until the dough holds together when pinched. Flatten into a 1-inch disk, wrap, and chill 30 minutes.

Step 2: Roll, fit, and blind-bake

Preheat the oven to 375°F (190°C). On a lightly floured surface, roll the dough into a 12-inch circle. Fit into a 9-inch pie plate, trim to a 1-inch overhang, fold under, and crimp. Prick the base with a fork. Line with parchment and fill with pie weights. Bake 20 minutes; remove weights and parchment and bake 10–12 minutes more until golden. Cool 10 minutes. Reduce the oven to 350°F (177°C).

Step 3: Cook the Okinawan sweet potatoes

Steam the cubed potatoes in a steamer basket over simmering water until very tender, 15–20 minutes. Spread on a tray for 5 minutes to let excess moisture evaporate—this keeps the custard silkier and prevents a watery layer.

Step 4: Blend the purple custard and bake

In a large bowl, mash the potatoes until smooth. Whisk in evaporated milk, sugar, cornstarch, melted butter, vanilla, lemon juice, salt, and optional cinnamon. Whisk in the eggs last. For an ultra-smooth texture, use an immersion blender 30–60 seconds. Pour into the warm crust. Bake at 350°F (177°C) for 30–35 minutes until the edges are set and the center has a slight wobble (or 175°F/79°C internal temp). Cool on a rack 30 minutes; the surface should be warm, not hot.

Step 5: Cook the haupia (coconut layer)

In a saucepan, whisk coconut milk, water, sugar, cornstarch, and salt until no lumps remain. Cook over medium heat, stirring constantly with a flexible spatula, until thick, glossy, and just beginning to bubble, 5–7 minutes. Remove from heat and stir in vanilla. The mixture should fall in thick ribbons and hold soft lines when stirred.

Step 6: Layer, level, and chill until set

Immediately pour the warm haupia over the warm sweet-potato layer. Smooth the top with an offset spatula. Chill uncovered 30 minutes, then cover and refrigerate until completely cold and sliceable, 3 1/2–4 hours (overnight is ideal).

Step 7: Whip, garnish, and slice cleanly

Beat cold heavy cream, powdered sugar, and vanilla to soft peaks. Dollop or pipe over the chilled pie. Sprinkle with toasted coconut flakes and a whisper of lime zest if using. For neat slices, dip a sharp knife in hot water and wipe between cuts. Serve cold.

Pro Tips

• Color boost: A touch of lemon juice stabilizes the purple anthocyanins for that vivid hue.
• No soggy bottoms: Blind-baking the crust fully prevents the custards from seeping in.
• Silky texture: Blend the sweet potato filling and strain if needed; whisk the haupia constantly to avoid lumps.
• Layer adhesion: Pour haupia while both layers are warm so they bond without separating.
• Clean slices: Chill thoroughly and use a hot, dry knife for picture-perfect layers.

Variations

• Macadamia shortbread crust: Swap crust for 1 1/2 cups shortbread cookie crumbs + 1/2 cup finely chopped macadamias + 6 tbsp melted butter; press and bake 10 minutes at 350°F.
• Dairy-free: Use coconut oil in the crust, full-fat coconut milk in the purple layer (1 cup), and skip the whipped cream or use coconut whipped topping.
• Extra coconut: Fold 1/4 cup finely shredded coconut into the haupia for gentle texture.

Storage & Make-Ahead

Refrigerate the pie, covered, for up to 3 days. The crust can be made and blind-baked 1 day ahead; keep wrapped at room temperature. The pie should not be frozen (haupia can weep after thawing). Whip the cream just before serving or up to 4 hours ahead and refrigerate.

Nutrition (per serving)

Approximate for 1 of 10 slices: 500 calories; 28 g fat (18 g saturated); 60 g carbohydrates; 30 g sugars; 3 g fiber; 6 g protein; 210 mg sodium. Estimates only.