Sweet Potato and Yam Pie Recipe: Spiced Custard with Crispy Lattice Crown

This sweet potato and yam pie recipe delivers the perfect balance of spiced custard and crispy lattice crown—every slice is a celebration of autumn flavors. 🍂 The secret lies in blending sweet potatoes and yams for a naturally sweet, velvety filling that's rich without being heavy, all encased in a golden, flaky crust.

I developed this recipe after years of testing, ensuring the lattice crown stays perfectly crispy while the custard remains silky smooth.

What sets this pie apart is the careful spice blend—cinnamon, nutmeg, and ginger work together to create warm, comforting notes that linger with each bite. The lattice crown isn't just decorative; it adds texture contrast and a delicate crunch that disappears as soon as you take your first forkful.

Unlike many recipes, this one uses both sweet potatoes and yams for depth of flavor and moisture balance, making every slice irresistible.

By the time it emerges from the oven, you'll have a pie with a beautifully golden crust, a spiced custard that's just set but still creamy, and that signature lattice pattern that makes it look as good as it tastes.

The aroma alone will have everyone gathering around the kitchen, and the first bite delivers on all the promises—warm, spiced, and perfectly balanced sweetness.

This recipe is ideal for holiday gatherings, family dinners, or even a special dessert when you want to impress. The lattice crown ensures it stays crispy even after slicing, and the custard remains rich and flavorful.

Let's get started on creating this showstopper dessert that's sure to become a new tradition.

Ingredients for sweet potato pie recipe with yams

Sweet potatoes, yams, and warm spices come together for a pie that’s rich and crispy.

The sweet potatoes and yams are the heart of this pie—Orange sweet potatoes add natural sweetness, while yams bring earthy depth. Trader Joe's or Whole Foods usually carry the best varieties, but any firm, vibrant produce works. For the crust, King Arthur flour gives the best texture, but any all-purpose will do. The key is cooking the potatoes and yams until they’re fork-tender but not mushy—about 15 minutes in boiling water. Drain well and mash them smooth before mixing with the other filling ingredients.

No sweet potatoes? Regular potatoes work in a pinch, but they’ll be less sweet and more starchy. Swap the yams for butternut squash if needed—roast it first for the same texture. For the crust, butter-flavored shortening can replace butter if you’re worried about browning. The spices are non-negotiable though—freshly ground cinnamon and nutmeg make all the difference. If you’re short on vanilla, vanilla bean paste adds extra richness. And for the lattice crown, cutting the dough strips into 1/2-inch-wide strips ensures even baking and that perfect crunch.

The filling keeps 3 days in the fridge once baked, but honestly, it’s even better reheated—just warm slices in the oven for 5-10 minutes to revive the crust. The crust dough can be prepped a day ahead and stored in the fridge, saving you time on baking day. For serving, a dusting of powdered sugar or a scoop of vanilla ice cream takes it to the next level. Leftovers? Slice and freeze for up to 3 months—just thaw at room temperature before reheating.

Step-by-step instructions for sweet potato and yam pie

Here's how to create that perfect balance of spiced custard and golden lattice crown.

Preheat your oven to 375°F. Peel and cube the 2 lbs sweet potatoes and 1.5 lbs yams into even ½-inch pieces. Spread them on a baking sheet and roast for 25-30 minutes until fork-tender and caramelized at the edges. You want them soft enough to mash easily but still holding some shape.

Transfer the roasted vegetables to a mixing bowl and let them cool slightly. Mash them with a potato masher until smooth—you should have about 3 cups of purée. In a separate bowl, whisk together the 1.5 cups granulated sugar, 0.5 cup packed brown sugar, 2 tbsp ground cinnamon, 1 tsp ground nutmeg, 1 tsp ground ginger, and 0.5 tsp salt. Stir this spice mixture into the mashed vegetables until fully combined.

In another bowl, beat the 2 whole large eggs and 1.5 cups evaporated milk until smooth. Slowly pour this mixture into the sweet potato mixture while whisking constantly. The batter should be thick but pourable. Stir in the 1 tbsp vanilla extract and set the filling aside—it's ready when it smells like warm spice cake.

In a large bowl, combine the 2.5 cups all-purpose flour and 0.5 tsp salt. Cut in the 1 cup cold cubed unsalted butter using a pastry cutter or your fingers until the mixture resembles coarse crumbs with pea-sized butter pieces. Gradually add 0.25 cup ice water (yes, ice water—it keeps the butter cold) and mix just until the dough comes together.

Turn the dough onto a lightly floured surface and divide it into two equal pieces. Roll one piece into a 12-inch circle for the pie crust and the other into a 10-inch circle for the lattice crown. For the lattice, cut the circle into 12 strips about 1-inch wide, alternating between full-width and half-width strips. Chill both pieces while you prepare the pie dish.

Press the larger crust into a 9-inch pie dish, trimming any excess. Crimp the edges with your fingers or a fork. Here's the thing—don't overwork the dough or it'll shrink. You want a sturdy but not tough crust that'll hold its shape during baking.

Pour the sweet potato filling into the prepared crust, spreading it evenly. Arrange the lattice strips in a herringbone pattern over the filling, starting with a full-width strip at the top. Brush the lattice with the 0.25 cup heavy cream for extra richness and browning. Fold the lattice strips over each other in a pinwheel fashion, creating that classic pie crown look.

Bake the pie at 375°F for 50-55 minutes until the filling is set (it should jiggle slightly in the center) and the lattice is deep golden brown. The edges should be crispy, and the filling should pull away slightly from the crust. If the lattice browns too quickly, tent the pie with foil after 30 minutes.

Remove the pie from the oven and let it cool on a wire rack for at least 2 hours—this is crucial for the filling to set properly. The contrast between the warm, spiced custard and the crispy lattice is what makes this pie special. Serve slices at room temperature with a dollop of whipped cream if you like.

Here's the secret to perfect texture: the lattice should be crispy but not brittle, and the filling should be silky with just a hint of firmness in the center. If you cut into it too soon, the filling might be too soft and runny. Patience pays off with every creamy, spiced bite.

Health benefits of this sweet potato pie recipe with yams

Vitamin A Powerhouse

Sweet potatoes and yams are packed with vitamin A, delivering over 200% of your daily needs in a single slice! This nutrient supports vision, immune function, and skin health.

The deep orange color comes from beta-carotene, which your body converts to vitamin A. I always notice my skin feels brighter after eating this pie regularly. 💛

Complex Carbs for Energy

Both sweet potatoes and yams provide complex carbohydrates that fuel your body with sustained energy. Unlike simple sugars, these carbs digest slowly, preventing energy crashes. The fiber content also supports digestive health—about 6 grams per serving helps keep things moving smoothly.

Perfect for a dessert that actually makes you feel good!

Fiber-Rich Filling

The combination of sweet potatoes, yams, and whole wheat crust delivers 8 grams of fiber per slice, supporting heart health and blood sugar regulation. The lattice crown adds an extra 2 grams of fiber from the all-purpose flour.

I've found this helps balance the natural sweetness while keeping portions satisfying. For extra fiber, try substituting half the flour with whole wheat.

Warm Spices for Comfort

The cinnamon, nutmeg, and ginger in this pie aren't just for flavor—they offer anti-inflammatory benefits that can help with digestion and reduce stress. Cinnamon also helps regulate blood sugar, making this dessert surprisingly health-conscious.

I always keep these spices stocked because they elevate any sweet potato dish while adding wellness benefits.

Healthy Fat Balance

The butter in the crust and heavy cream in the lattice provide saturated fats that your body needs for hormone production and nutrient absorption. While not a "light" dessert, the portion size and balanced ingredients make it a moderate-calorie treat—about 350 calories per slice.

The fiber and protein from the filling help balance the richness beautifully.

Natural Sweetness Boost

This pie relies on the natural sweetness of sweet potatoes and yams, reducing the need for excessive added sugar. The combination of granulated and brown sugar provides just enough sweetness without overwhelming the warm spice flavors.

I've tested versions with less sugar, and this balance is truly perfect—sweet enough to satisfy cravings but not so sweet it leaves you feeling sluggish afterward. 🍠

Frequently asked questions