Cut the peaches lengthwise, remove the pits. Sprinkle slice with rum, sprinkle with cinnamon. Puree raspberries with sugar and lemon juice in a blender, strain through a fine sieve to remove seeds, and cool. Grill the peaches over medium charcoal, cut side down, for 2-3 minutes until grate marks appear. Turn over and bake until soft. Arrange peaches cut side up on plates, drizzle with raspberry sauce and garnish with mint leaves.