In a mixing bowl, use a whisk to mix the apple butter, evaporated milk, eggs, sugar, brown sugar, cornstarch, cinnamon, nutmeg, and salt until smooth.
Pour the filling into the unbaked pie crust.
Bake in a preheated oven at 400°F for 15 minutes. Then, lower the heat to 350°F and bake for an additional 40 minutes, or until the center is set. If you insert a knife into the center, it should come out clean.
Allow the pie to cool completely on a wire rack before slicing. Serve each slice with whipped cream, if desired.