To make gingerbread dough, cut out paper triangle template. Line 4 baking trays with parchment paper. Make cookie dough: place butter and sugar into a large mixing bowl. Using an electric mixer beat until light and creamy, about 6 minutes. Add golden syrup, egg yolks, sifted flour, ginger, cardamom, cinnamon, and baking soda. Beat until mixture forms soft dough. Turn onto a floured surface and knead to a smooth dough. Divide dough into 2, flatten each into a disc shape, wrap in plastic wrap, and place into refrigerator for 10 minutes. Preheat oven to 350°F. Working in batches, roll dough between 2 sheets of parchment paper to 1⁄8” thickness. Transfer rolled dough piece on the sheet of parchment paper to a tray and freeze for 15 minutes. Remove from freezer and slide onto workbench with its parchment paper. Place template onto dough and cut around using a ruler and sharp knife. Repeat until you have cut 12 triangles. Place onto a tray and return to freezer for 15 minutes or until firm. Remove from freezer then remove the dough trimmings from around the triangles edges. Reserve these trimmings and wrap in plastic and refrigerate. Place gingerbread triangle pieces onto prepared trays; allow a little room for spreading. Repeat with remaining dough until you have 24 triangles in total. Re-roll the reserved trimmings of dough and cut 6 small stars using a 2″ star cookie cutter. Place star cookies onto a separate baking tray as they will take less time to cook. Bake gingerbread in preheated oven for 10–12 minutes or until golden. Allow gingerbread to cool completely on trays. To make the royal icing: place egg white into a medium mixing bowl; use a fork to beat until foamy. Gradually beat in icing sugar with a wooden spoon until you have a very stiff paste. Cover with a damp tea towel until ready to use. To assemble Christmas trees, think of the icing as glue (i.e. use plenty). Spoon royal icing into a plastic sandwich bag seal then use scissors to snip a small corner off. Pipe icing along the 2 long edges of a triangle. Hold triangle shortest side down (the edge without icing) on a work board, attach 2 gingerbread triangles to the iced edges (you may need to use a small bottle to help the gingerbread pieces stand up). Again, pipe icing along the sides of a 4th gingerbread triangle and attached to the gingerbread tree edges to form a pyramid shape. Repeat with remaining gingerbread pieces to make 6 Christmas trees. Allow to stand for 15 minutes or until icing sets. Pipe some icing onto the back of each star and attach stars to ginger- bread trees.