Line 2 muffin tins with paper cases (I used one 12 hole pan and one 6 hole pan)
Sift the flour and cocoa together into a large bowl
Stir in the sugar
Make a well in the centre
Whisk together the milk, egg, melted butter, yoghurt and vanilla extract
Pour into the well and fold in gently with as few strokes as possible
Stir in the chocolate chunks and the blackberries
Spoon the muffin mix evenly between the paper cases
Bake in the preheated oven for 20 - 25 mins until risen and a skewer inserted into a muffin comes out clean.
Serve warm as they are or cold with a blob of greek yoghurt and a blackberry on top
Notes
Nutritional information is only an approximate guideline. Calculations will vary according to the ingredients you use and your cooking methods.These muffins will keep well in a cake tin for two or three days - if they last that long!