Place rhubarb and apple into a medium sauce pan with just enough water to cover the bottom of the pan. Bring to boil and simmer for 15 min (check water level occasionally to ensure it has not boiled off, add more if it does). Remove from heat, add remaining ingredients and blend with an emulsion blender or regular blender.
Optional: add a few tablespoons of chia seeds to thicken
Place in jar and store in refrigerator or freezer.
Excellent spread on muffins, bread/toast or granola bars, as well as, topping on oatmeal, porridge, parfait or granola.