Preheat the oven to 350 degrees F. Butter a 9-inch-square baking dish.
Toss the cherries in a large bowl with 1/2 cup sugar, the rum, vanilla, cinnamon, salt and 2 tablespoons flour. Transfer to the prepared baking dish.
Whisk the remaining 1/4 cup flour, the oats, almonds and the remaining 1/4 cup sugar in a medium bowl. Stir in the melted butter until combined, then sprinkle the mixture over the cherries. Bake until the filling is bubbling and the topping is golden brown, 50 minutes to 1 hour. Let cool slightly before serving.