In a small saucepan, bring raisins, rum, and water to a boil over medium-high heat.
Reduce heat to low, and simmer for 2 minutes.
Remove from heat, and let sit for 30 minutes. Drain remaining liquid.
Arrange pie crust in a 9-inch pie plate, and crimp or scallop the edges.
In a large bowl, whisk together brown sugar, flour, cinnamon, nutmeg, and salt.
Add eggs, corn syrup, melted butter, vanilla, oats, and raisins.
Pour into prepared crust.
Bake at 350 degrees for about 45 minutes, or until edges are golden, and the center appears set.
Set on a wire rack to cool completely. Cut and serve.
Garnish with whipped cream.