Everything Nice ...

• The amounts called for in sweet potato pie and pumpkin pie are virtually interchangeable, allowing you to substitute an equal amount of sweet potato for pumpkin. Opt for half-and-half instead of the evaporated milk that many pumpkin pie recipes specify. The extra fat in half-and-half helps sweet potatoes better approximate the silky quality of pumpkin pie. Use the same amount of half-and-half as you would evaporated milk. Similarly, you don't need to vary the amount of eggs used in the filling.

... Plus Sugar and Spice

• Traditionally, sweet potatoes are paired with brown sugar, and pumpkin pie with white sugar. Whichever you choose, leave out a spoonful or two of sugar; the naturally sweet spuds need less sugar than pumpkins do. Tone down the spice mix when substituting sweet potatoes. Rather than using a complex pumpkin pie blend that includes spicier notes of ginger and cloves, it's more traditional to pair sweet potatoes with a simple blend of 2 parts cinnamon to 1 part allspice. The total amount of spices in your sweet potato pie should equal the total amount used for pumpkin pies.