1. Drain all of the peach juice into the blender jar. Sprinkle in the gelatin powder and let sit (1 minute).
2. In a small saucepan, heat the apple juice until just steaming.
3. Add this to the blender jar with gelatin mixture. Blend on high, being sure to keep the vent open and covered loosely with a towel.
4. Add peaches and cinnamon and blend until smooth. Transfer to a storage container and refrigerate until set (1 hour).