Marshmallow Christmas trees

Method

• Step 1
  Place flour, cocoa, brown sugar and butter in a food processor. Process until mixture resembles fine breadcrumbs. Add egg yolk and milk. Process until mixture just comes together. Turn out onto a lightly floured surface. Gently knead until mixture is smooth. Divide mixture in half. Shape into 2 discs. Wrap in plastic wrap. Refrigerate for 20 minutes.
• Step 2
  Preheat oven to 170C/150C fan-forced. Line 2 baking trays with baking paper. Roll out 1 dough disc between 2 sheets of baking paper until 5mm-thick. Using a 4.5cm round fluted cookie cutter, cut rounds from dough, re-rolling and cutting trimmings. Place, 2cm apart, on 1 prepared tray.
• Step 3
  Bake for 12 minutes. Cool on tray for 5 minutes. Transfer to a wire rack to cool completely. Repeat with remaining dough disc and prepared tray.
• Step 4
  Place caster sugar and 2/3 cup cold water in a saucepan over medium heat. Cook, stirring, until sugar dissolves. Bring to the boil. Reduce heat to medium-low. Simmer for 5 minutes or until mixture thickens slightly. Remove from heat. Sprinkle gelatine over boiling water in a heatproof jug. Whisk with a fork until gelatine dissolves. Add to sugar syrup. Stir to combine. Set aside for 5 minutes to cool slightly. Transfer mixture to the bowl of an electric mixer. Add vanilla and food colouring. Beat on high speed for 5 minutes or until mixture becomes fluffy and thickens. Don’t over-mix.
• Step 5
  Working quickly, spoon mixture into a piping bag fitted with a 1cm fluted nozzle. Pipe mixture onto each biscuit to form a Christmas tree shape. Sprinkle with stars and hundreds and thousands. Set aside for 1 hour or until set. Serve.