step 1
Preheat the oven to 180C. Line 24 muffin tins with muffin cases.
step 2
Mix together eggs and sugar until light and fluffy. Add yogurt and butter, and mix until combined.
step 3
In a seperate bowl combine the flour, cocoa, baking powder and bicarbonate of soda. Sieve into the egg mixture and mix well with the hand mixer.
step 4
Add chocolate chunks and stir them in with a spoon.
step 5
Spoon the mixture into 24 muffin cases. Bake for 15 minutes. Remove from the tins and cool on the wire rack.