Begin by making the compote. Preheat the oven to 160 celsius (320 Fahrenheit). Place the compote ingredients into a roasting pan lined with baking paper and toss to combine. Bake for 25 minutes, or until soft.
Increase the oven temperature to 200 celsius (400 fahrenheit). Place the flour, baking powder and raw sugar in a bowl and whisk to combine. Combine the liquid ingredients in a jug and whisk to ensure the egg is well incorporated. Add the wet ingredients to the dry and stir until just combined. Measure out 1/3 cup of the rhubarb mixture and add to the batter and stir through. Carefully grease and flour a 6 cup muffin pan and divide the mixture between each cup. Top with a little more of the compote and bake for 20 to 25 minutes, or until lightly golden and a cake tester comes out cleanly when inserted into the middle of each muffin.
Carefully remove the muffins from the pan and leave until warm and serve with the remaining compote.
You can easily double this recipe. Don't have raw sugar or spelt flour? Simple replace them with plain white flour and regular sugar. Whole wheat spelt flour is worth seeking out though and can often be found in supermarkets these days.