Preheat oven to 190C (375F). For fan forced oven reduce temperature by 20C or 40F. Line 9 holes of a large muffin tray with papers.
Combine flour, baking powder and sugar in a large bowl and make a well in the centre
Melt butter then remove from the heat. Stir through yoghurt and water and then add eggs, stirring well afterwards.
Pour butter mixture into the well in the dry ingredients and stir to combine. Don’t stress if there are a few flour lumps. Fold through raspberries and chocolate and spoon into prepared muffin papers. Sprinkle with raw sugar.
Bake for 30 – 45 minutes or until muffins are lightly golden and feel firm and spring back when you push them gently on the top. Allow to cool in the tray. Especially good while still warm and the chocolate is all molten but will keep for up to a week in the fridge.