Grandma's Old-Fashioned Sweet Potato Pie
Grandma's sweet potato pie was the one dish nobody was allowed to bring a store-bought version of. Deep, spiced and silky, in a proper buttery crust — it held the corner of every holiday table, and there was never, ever enough of it.
The secret she'd share, if you asked nicely, was this: roast the sweet potatoes, never boil them. Boiling waterlogs the flesh and gives you a pale, loose filling; roasting drives off the water and concentrates the sugar into something deep and almost caramel. The second secret was patience at the oven door — bake it low and pull it while the centre still wobbles. An overbaked custard tightens and cracks; this one sets silky as it cools.
Chill it properly before slicing, top with softly whipped cream, and understand why it always disappears first.
Grandma's Old-Fashioned Sweet Potato Pie
Deep, spiced and silky in a buttery crust — made the right way, with roasted sweet potatoes.
Ingredients
- 1 x 23 cm shortcrust case, unbaked
- 600 g sweet potatoes (about 2 large)
- 75 g butter, softened
- 120 g soft brown sugar
- 2 eggs
- 150 ml evaporated milk
- 1 tsp vanilla
- 1 tsp cinnamon, ½ tsp ginger, ¼ tsp nutmeg
- Pinch of salt · whipped cream to serve
Method
- Roast, don't boil. Oven to 200°C (fan 180°C / gas 6). Prick and roast the whole sweet potatoes 45–60 minutes until soft. Cool, scoop out 400 g of flesh, mash smooth.
- Blind-bake. Line the case with paper and beans; bake at 190°C (fan 170°C / gas 5) 15 minutes, remove beans, 5 more. Keeps the base crisp.
- Filling. Beat the mash with the butter and brown sugar until smooth, then the eggs, evaporated milk, vanilla, spices and salt until silky.
- Bake low. Pour in and bake at 180°C (fan 160°C / gas 4) 45–55 minutes — set at the edge, slight wobble in the centre. Low + slightly underdone = no cracks.
- Cool & chill. Cool fully, then chill at least 2 hours to a sliceable, silky custard. Whipped cream, and stand well back.
Roast the sweet potatoes a day ahead — cold, they mash smoother and the pie comes together in fifteen minutes.
Tips for a silky, crack-free pie
Roast for depth
Roasting concentrates the sugar and drives off water — a richer, firmer-setting filling.
Pull it wobbling
A slight tremble in the centre means it'll set silky. Bake it firm and it cracks.
Blind-bake the base
A pre-baked crust stays crisp under the custard instead of turning to paste.
Questions, answered
Sweet potato pie vs pumpkin pie?
Cousins that eat differently — sweet potato pie is denser, fluffier and more custardy with a deeper natural sweetness; pumpkin pie is smoother and softer. Grandma's table always had the sweet potato one.
Why roast instead of boil?
Boiling waterlogs the flesh and dilutes the flavour, leaving the filling loose and pale. Roasting concentrates the sugars for a richer, firmer pie.
Why did my pie crack?
Baked too hot or too long — an overcooked custard tightens and splits. Moderate heat, and pull it with a slight wobble; it finishes setting as it cools.
Can I make it ahead?
It's better for it — bake a day ahead, cool and chill. The flavour deepens and it slices cleanly. Serve at cool room temperature.