Combine the sugar, butter, spices, and salt together in a microwaveable dish. Heat long enough to melt the butter. Stir in the rum.
Place the apples, pears, lemon juice, and raisins in a large bowl. Toss with the butter-rum mixture until the fruit is completely coated. Pile half of the fruit into the pie shell. Arrange the remaining half of the fruit on top.
Preheat the oven to 350˚F. Place the pie on a baking sheet - just in case it bubbles over, and bake until bubbly - about 50 minutes. Be sure to check the crust after 25 - 30 minutes. You may need to cover it with foil to keep it from over-browning.