Start by making sure your creme eggs are frozen solid (AT LEAST 1 hour) - I do mine overnight though.
Prep 4 x 8cm pudding moulds by brushing the melted butter all over the inside of the mould - I use a pastry brush for this.
Dust the inside with the cocoa powder, making sure the cocoa powder covers all of the melted butter and tapping out any excess cocoa powder.
Fondants
Preheat the oven to 200ºc/180ºfan.
In a small bowl, add the dark chocolate and unsalted butter and melt until smooth - I do this in the microwave.
Once melted, leave it to cool for 10 minutes.
In a new bowl, add the light brown soft sugar, eggs and egg yolks and whisk together for a couple of minutes, until the colour of the mixture is much lighter and the whisk leaves a trail in the mixture when it is lifted out of the bowl.
Pour in the chocolate/butter mixture, and stir until smooth.
Add in the plain flour, and stir until smooth again.
Split the mixture evenly between the four pudding moulds, and carefully press in a frozen creme egg (on it's side). Press the creme egg in fully, and cover the top if you can still see it with mixture.
Once the creme eggs are covered, place the fondant's in the oven and bake for 11-13 minutes.
Take them out of the oven and let them cool for 10 minutes in the pudding moulds, and then turn out and serve immediately.