Begin by preheating your oven to 350°F. Place your whole sweet potatoes on a baking sheet and roast them for 45 to 60 minutes, or until they are extremely tender when pierced with a fork. Roasting gives the potatoes a deeper caramelized sweetness that boosts the flavor of the pie. Once they’re done, let the potatoes cool until they’re comfortable to handle.

When the potatoes have cooled, peel them and transfer all the flesh into a mixing bowl. Mix on low speed for one to two minutes, then increase to medium for another two to three minutes until they become smooth, fluffy, and mashed-potato-like in consistency.

Next, pour in the melted butter and whole milk. Continue mixing until the filling becomes silky and fully combined, creating the rich, custard-like base of the pie.

Add the cinnamon, nutmeg, allspice, flour, brown sugar, half of the white sugar, and a pinch of salt. Mix well, then taste the filling and adjust the sweetness with more white sugar if needed. It’s important to taste the mixture at this stage before adding the eggs.

Once the sweetness is right, mix in the vanilla extract, butter extract, lemon extract, and fresh lemon juice. The lemon brightens the pie and balances the warm spices and sweetness perfectly.

Now add the eggs and blend until smooth. Prepare your two deep-dish pie shells according to package directions. Divide the filling evenly between both shells so they are nicely full but not overflowing.

Bake the pies at 350°F for 90 to 110 minutes. They are finished when the center has a light jiggle, the edges are set, and the internal temperature reaches 175°F. Ovens vary, so begin checking the pies around the 90-minute mark.

Allow the pies to cool at room temperature for at least two hours so the custard can fully set. For the cleanest slices, chill them overnight.