Half an hour or more before making the muffins, unwrap the creme eggs and put them in the freezer.
Using a fork, mash the bananas in the bottom of a large mixing bowl until they have become a puree.
Add all the rest of the ingredients. Sift in the cocoa powder if it is lumpy. Fold together until everything is just combined. Don't overmix.
Line a muffin tin with muffin cases.
Put a spoonful of mixture in the bottom of each case. Put a creme egg in the middle of each one. Top with another spoonful of mixture. The cases should be about two thirds full.
Bake in a preheated oven at 160C for 20 minutes.
Cool for a few minutes in the tin then transfer the muffins to a wire rack to finish cooling.
Replace the creme eggs with another type of chocolate coated mini egg in the middle of each one. To make banana and chocolate chip muffins, replace the creme eggs with 70g chocolate chips stirred into the mixture at the end.Nutritional information is approximate and a guideline only.