1. Put the rhubarb and apple in a large pot with a small amount of water, and simmer for about 15 minutes, or until the fruit is soft.
2. Add the orange zest, cinnamon, nutmeg, and syrup, and stir to combine. Leave it on the heat for another 5 minutes. If you're using the fruit as a jam, you can cook it longer so that the fruit gets softer and almost falls apart.
3. If you're making a crumble, preheat oven to 350 degrees F. Spoon the filling into a large baking dish, and mix in the 1/4 cup oats. For topping, put the oats in a bowl, stir in the cinnamon and sugar, if using dry.
4. Add about 1/4 cup boiling water, just enough to moisten them, and add the syrup, if using. Stir so that the oats soften and swell.
5. Sprinkle the topping mixture over the fruit, and put the dish in the oven for 15-20 minutes, or until the oats are starting to brown.
Source of recipe: To watch a free video of me making this rhubarb apple crumble, so I can show you the exact techniques that will make the perfect recipe, go to http://www.healthyveganrecipes.net/video/rhubarb-apple-crumble [1]