Line the inside of a loaf tin with baking paper
Place the biscuits into a plastic bag and crush. I use Scotch Finger biscuits
Melt the butter in a saucepan over a low heat.
Beat the egg and sugar in a bowl and then add the melted butter. Beat until the mixture is smooth and lemon in colour.
Melt the chocolate and add it to the egg mixture. Whisk or beat together until smooth and fully combined. (if you don't combine it properly you can end up with butter pockets in your slice).
Stir in the biscuit pieces and the marshmallows.
Press into tin and smash up your mini eggs.
Sprinkle them over the top of the slice and refrigerate until set. (At least 2 hours)