1) Coat an outdoor grill or stove-top grill pan with cooking spray and preheat to medium-high.
2) Arrange orange slices on hot grill and grill 2 minutes per side, until golden brown.
3) In a medium bowl, combine fudge sauce and raspberry preserves. Cover and microwave on HIGH for 30 seconds, until warm.
4) Spoon frozen yoghurt over orange slices and drizzle raspberry-fudge sauce over top.