Put the raisins in a small bowl, and pour the rum over them. Let them soak while you make the pancake. Preheat the oven to 400 degrees.

Whisk the egg whites in a stand mixer fitted with the whisk attachment on medium speed until theyre foamy. Increase the speed to high, and stream in 6 tablespoons of the sugar. Whisk them to form soft peaks, about 2 minutes. Set them aside.

In a large bowl, whisk the egg yolks with a pinch of salt to break them up. Whisk in the milk, vanilla, and orange zest until the mixture is smooth. Whisk in the flour just until its smooth. Whisk in 3 tablespoons of the melted butter. Fold in about a third of the egg whites with a rubber spatula to lighten the batter; then fold in the remaining whites, taking care to keep the batter light by not overmixing.

Heat a large nonstick skillet over medium heat. Brush with a little of the remaining melted butter. Pour in the batter. Drain the raisins, reserving any excess rum, and scatter the raisins over the top of the batter. Cook until the edges begin to set, 2 to 3 minutes; then bake until theyre puffed and golden and a tester comes out clean, 15 to 17 minutes.

Transfer the skillet to the stovetop over medium heat. Use a big offset spatula to cut or break the pancake into cubes. Flip them to loosen them up; then drizzle them with the remaining melted butter and sugar. Cook and toss until the edges of the cubes are caramelized and golden, 3 to 4 minutes.

Warm the jam with the reserved rum in a small skillet over low heat, and stir this to combine. Divide the Kaiserschmarrn among serving plates, dust them with confectioners sugar, drizzle with the jam sauce, and serve.