Chocolate bat biscuits

Let a friendly bat perch on your glass of milk or cuppa this Halloween with these spooky biscuits - add vanilla buttercream for bourbons
Ingredients
    125g butter, softened
    85g icing sugar
    1 large egg yolk
    1 tsp vanilla extract
    1 tsp milk
    175g plain flour, plus extra for rolling
    1 tsp fine espresso-style powder coffee (I used Azeera)
    50g cocoa powder
    ¼ tsp salt
To decorate
    100g bar dark or milk chocolate
    chocolate hundreds and thousands
    coloured writing icing (or make your own with 100g icing sugar, 3-4 tsp water and some colouring)
Method
    Heat oven to 180C/160C fan/gas 4 and line two baking sheets with baking parchment. Beat the butter and sugar together until creamy and pale, then beat in the yolk, the vanilla and milk. Sift the flour, coffee, cocoa and salt into the bowl, then mix together to make a soft dough. Shape the dough into a disc, wrap and chill for 15 mins.
    Dust the dough all over with a little flour, then roll it between two large sheets of baking parchment, to the thickness of a £1 coin. Remove the top layer of the paper, stamp shapes with an 8cm bat (or other) cutter, and carefully lift to the lined sheets using a palette knife. Re-roll the trimmings. Cut a 1.5cm x 5mm notch at the base of each bat’s body. This is about right to sit the bats on thick tumblers; if your glasses are finer-edged, make the notches thinner so that the bats stay put. Bake for 10 mins or until the biscuits feel sandy and smell rich and chocolatey. Cool on the sheets for 5 mins, then lift the cookies onto a wire rack and cool completely.
    To decorate, melt the chocolate over a pan of simmering water or in the microwave. One biscuit at a time, brush chocolate over the bat ears and wings with a small paintbrush, then cover with chocolate sprinkles. Tap off the excess. Pipe faces and fangs onto your bats, then leave to dry. Keep in an airtight container for up to a week.
Source: My Good Food