Place the golden syrup, treacle, light brown sugar, coconut oil or margarine and water in a pan.
Heat gently while stirring until the coconut oil/margarine has melted. Whisk in the cinnamon, ginger, cloves and bicarbonate of soda then stir in the plain flour until it forms a soft dough and no pockets of flour remain.
Re-roll the trimmings and cut out more shapes then place them well spaced apart on a couple of baking trays. Pop the trays in the freezer for twenty minutes while you heat up the oven to 180C/350F/gas mark 4.
To make the royal icing, mix the little lemon juice and aquafaba into the sifted icing sugar until it forms a thick but pourable consistency. If you drizzle some back into the bowl the pattern should disappear after about 8-10 seconds. If it is too thick then stir in a little more aquafaba or lemon juice, and if it is too runny then mix in some more sifted icing sugar.
Once the icing is dry the biscuits can be stored in an airtight container for at least a week.
Preheat the oven to 180C/350F/gas mark 4. Grease three 20cm/8in round cake tins and line the bases with baking parchment.
Whisk together the sifted plain flour, baking powder, bicarbonate of soda, ginger, mixed spice, caster sugar and salt in a large bowl.
Add the golden syrup, treacle, sunflower oil and boiling water to the bowl and whisk until no lumps of flour remain.
Divide the batter between the prepared tins and bake for about 25 minutes, until a skewer inserted into the centre comes out clean.
Leave to cool in the tins for 10 minutes then transfer to a wire rack to cool completely.
Don't make the buttercream until you are ready to assemble the cake. Whisk together the vegetable shortening and dairy free cream cheese until smooth.
Add the sifted icing sugar, fresh lemon juice and vanilla extract and whisk until smooth. If the frosting is too soft then you can whisk in some more sifted icing sugar; and if it is too stiff then you can add a drop more lemon juice or a little non-dairy milk.
Trim the tops of the cake layers to level them (a cake wire is best for this) then place one layer on a serving platter or board.
Spread over a thin layer of the buttercream then pipe a wide ring of buttercream around the edge of the cake. You can also add a blob in the middle to help make the cake more sturdy (I didn't do this but in hindsight I should have done!).
Spread a layer of buttercream over the top and sides of the cake, use a bench scraper or palette knife to get the sides smooth but leave the top rough so it looks snowy.
Cut a slit in the top of the cake where you want each of the trees to go and press a tree trunk into each one. Insert a wooden skewer into the cake close behind each tree to hold them up. (You will probably need to trim the skewers a bit to get the right height but make sure that they will go all the way through the cake and leave enough sticking out to hold the trees up.)
Use blobs of any leftover frosting to stick animal biscuits around the cake and place one on top of the cake (I just leant my fox against one of the trees).
Add sugared cranberries, sprigs of rosemary, hazelnuts, pecans and pumpkin seeds to complete the look.
Best served the day it is assembled but any leftovers will keep in an airtight container for up to five days.