Preheat the oven to 200°C.
Place the rhubarb and 50g of the coconut sugar in a pan with 100ml of water, bring to the boil then reduce to a simmer for 15-20 minutes until cooked through and all the water has evaporated.
Mix the flour, baking powder and bicarbonate of soda together with a pinch of salt. In the food processor mix the remaining 125g of coconut sugar and the butter/coconut oil together, add the egg, yogurt and vanilla. Then add in the flour mixture. Mix until fully combined, stir through the rhubarb by hand, leaving a little the side to place on top of the muffins.
Pour into greased or lined muffin tray. Bake for 18 minutes then leave to cool, serve with yogurt, fresh berries and a smile.