I spent several years learning the art of pie making at Four & Twenty Blackbirds, a beloved bakery located in Brooklyn, NY. Come fall, customers swiftly turned their attention to the signature salted caramel apple pie, but I was a steadfast fan of their sweet potato–apple crumble. Inspired by that combination, this pie marries sweet potatoes and apples with a mix of spices—including cinnamon, Chinese five-spice powder, and white pepper—and generously tops it with a punchy almond and thyme-spiced crumble.
For the apples, I took a cue from Stella, who exclusively calls for tart apples (like Granny Smiths) in her old-fashioned apple pie recipe. Combining apple slices with brown sugar and spices and allowing the mixture to macerate for three hours reduces its volume, which means more raw fruit can fit into a single pie. When baked, Granny Smiths hold their shape well, deliver a slightly tart bite, and complement the tender texture of sweet potatoes.
With the sweet potatoes, I tested several methods in order to pinpoint one that delivers a soft, supple texture. First, I tried par-boiling whole peeled sweet potatoes (the same method employed by Four & Twenty Blackbirds), which sometimes resulted in thoroughly tender ones but were more often either inconsistently cooked, with mushy exteriors and raw interiors, or completely overcooked. To shorten the cooking time and improve reliability, I opted to slice the sweet potatoes into smaller pieces that cook through faster and more consistently. The result is crisp-tender pieces that become perfectly cooked once baked.
A couple other notable techniques I tested for the sweet potatoes that didn’t make the cut: Kenji’s method of par-cooking sweet potatoes at low temperatures, which enhances their sweetness, produced ones that were too sweet in the context of this pie; microwaving the sweet potatoes, meanwhile, yielded mixed results—while the technique works well for fully cooking a sweet potato until soft and silky, it’s not nearly consistent enough when the goal here is par-cooking.
To finish the pie is a nubby crumble topping, made by combining flour, sliced almonds, sugar, thyme, salt, spices, and a liberal amount of melted butter. The result is a show-stopping pie that not only will be a welcome addition on the holiday table, but pulls off the remarkable feat of satisfying both apple pie lovers and sweet potato pie lovers alike.