• Preheat the oven to 170°C.

Preparing the dough

• Finely chop the candied orange peel.

  In a saucepan, melt the butter with the honey, treacle and 25 g of sugar.

  Once the butter has completely melted, turn off the heat and add the spices, chopped candied orange peel and vanilla extract.

  Leave to cool.
• Meanwhile, sift the two types of flour, baking soda and pinch of salt into a mixing bowl.
• Make a well in the flour and pour in the contents of the saucepan. Break an egg and beat it into the honey/butter/spice mixture.

  Add the remaining 25 g of brown sugar.

  Gradually mix in the flour until you obtain a smooth, even ball of dough.
• Leave the dough to rest for 30 minutes in the refrigerator.
• Roll out the dough with a rolling pin until it is 4–5 mm thick. (You can place the dough between two sheets of baking paper to make it easier to roll out).

  Using a sharp knife, cut out the Christmas trees in a staggered pattern (the trees in the photo are 10-12 cm high and 5-6 cm wide). Place them on an oiled or baking paper-lined baking tray, spacing them slightly apart (they will rise slightly during baking).
• Bake for 13 to 15 minutes until the biscuits are golden brown.
• Once out of the oven, brush on a thin layer of milk (optional) and leave to cool on a wire rack.

Making the icing

• Prepare the icing by gradually adding the egg white, teaspoon by teaspoon, to the sifted icing sugar. Mix vigorously until you obtain a relatively thick consistency and soften it slightly with a few drops of lemon juice. The icing is at the right consistency when it is smooth and thick and forms a ribbon when dropped. If it is too runny, add more icing sugar and whisk again.
• Using a piping bag and a fine plain nozzle (2 mm, for example), decorate the biscuits as shown in the illustrations, if you wish.

  Leave the icing to dry for 15 to 20 minutes before handling the biscuits.