Preheat the oven to 190 degrees C. In a small bowl combine raisins and rum to soak.
Mix the cinnamon and sugar together. Sprinkle half of it over the apples in a mixing bowl and toss well.
Dust a countertop with flour and roll out one sheet of pastry. Sprinkle with half of the remaining cinnamon sugar. Place half the apples and half the raisins along one edge, then roll up the pastry, covering the apples. Pinch together the ends and tuck under, then transfer to a baking tray. Repeat with remaining ingredients to make a second strudel.
With a sharp knife, make a few diagonal cuts across the top of the strudels to let out steam. Brush with melted butter then bake until puffed and golden, about 40 minutes.