Add flour, cocoa, bicarbonate of soda and salt to a bowl and use a whisk to combine.

Add the wet ingredients to a separate bowl and whisk until combined. Add the dry ingredients to the wet ingredients and fold until just combined.

Prepare a muffin tray with cupcake liners, spray them well with cooking spray then evenly distribute the batter between the 6 cups. Smooth out the tops and bake for 15 minutes.

Set aside the cupcakes until cool, then add the nutella and yoghurt to a small bowl and mix with a fork until smooth. Create holes in the centre of your cupcakes, using a piping nozzle or knife, then fill each hole with the nutella mixture.

Add the frosting ingredients to a bowl and use an electric whisk to beat until smooth. It should be thick, but pipeable. Add more protein to thicken or more yoghurt if the mix is too dry.

Transfer the frosting to a piping bag and pipe onto your cupcakes. Top with some grated chocolate if you like.