Crisp biscuit, soft caramel, and chocolate – these are so moreish, you’ll want to eat not just a finger, but a handful! If you can’t find candy melts, use all white chocolate and colour it with green food-colouring gel.
Make the biscuits. Beat the butter together in a stand mixer fitted with the beater, on medium speed for about 5 minutes, until creamy. With the mixer on a low speed, add the icing sugar and mix until fluffy. Then, add the egg yolks and mix until combined. Finally, add the flour and matcha powder and mix to a smooth dough.
Remove the dough from the bowl and form into a 7 x 48cm rectangle, about 1cm thick. Wrap in cling film and chill for 15 minutes. Heat the oven to 180°C/160°C fan/Gas 4.
Place an almond in one end of each of the hollows in the biscuit moulds (to form the nail). Cut the dough into 1cm slices and place one slice inside each hollow so that each hollow is no more than three-quarters full. Place the moulds on a baking tray and bake the biscuits for 12–15 minutes, or until edges of the biscuits start to brown. Remove from the oven and set aside to cool on the tray.
Start the caramel. Put the butter and sugar in a small non-stick pan over a low heat. Stir continuously with a wooden spoon to dissolve the sugar. Add the condensed milk and bring to the boil. Boil for about 1 minute, stirring continuously to prevent the mixture catching, until you have a golden caramel. Pour about half a teaspoon of caramel over each finger biscuit, leaving just enough space at the top for a final chocolate coating. Freeze the biscuits for 15 minutes to a soft set.
Make the shells. Place the white chocolate and candy melts in a heatproof bowl set over a pan of gently simmering water. Stir until melted, then remove from the heat and pour a little chocolate over each chilled finger. Spread the chocolate with a palette knife to remove the excess and place the biscuits back in the freezer for 10 minutes, until firm.
Turn the fingers out of the moulds and place them on a wire rack set over a sheet of baking paper. Spoon a little of the melted chocolate mixture over each finger to coat evenly (if necessary, re-melt the mixture that drips onto the paper below). Chill to set.
To make the edible blood, mix together all the ingredients in a small bowl. Spoon the mixture into the small piping bag, nip the end and pipe around the nails to resemble blood. Refrigerate the fingers until ready to serve.