• To Make the Madeleines
• In a small saucepan or in a microwave, melt the butter. Brush your madeleine tray or mould with some of the melted butter, and put to one side.
• Add the eggs and caster sugar together into a large bowl, and beat with a hand mixer or in a stand mixer for 5 minutes until they are pale and fluffy. 
• In a separate bowl sieve together the cocoa powder, plain flour and baking powder, then gradually fold into the egg mixture. When combined, add the remaining melted butter, and mix together well to form a smooth cake batter.
• Cover the mixture and leave to rest for at least 30 minutes to firm up.
• Preheat your oven to 180C
• To fill the madeleine mould either use a tablespoon and add a heaped spoon of the mixture to each shell or fill a piping bag and pipe the mixture instead. Make sure you don't overfill the moulds.
• Push a mini marshmallow into the centre of each madeleine.
• Bake the madeleines in the oven for 10-12 minutes, until they have risen and the tops spring back when pressed lightly. Take the madeleines out of the moulds and leave them to cool on a wire rack.

To Decorate the Madeleines

• Whilst the madeleines are cooling, break the chocolate into small pieces and gently melt in a microwave or place the bowl over a pan of simmering water and gradually melt, stirring until smooth.
• Dip each madeleine into the chocolate, so that it covers the pointy end and then set back on the wire rack to set. Before the chocolate sets, sprinkle over the crushed digestives.
• Keep them in an air-tight containers for 1-2 days, they dry out quickly!