Preheat oven to 180°C and grease and line three cake tins.
Sift flour and ground almonds into a bowl for the squirrel cake.
Cream butter and sugar until fluffy, then beat in eggs and a portion of the flour mixture.
Fold in remaining flour, almonds, baking powder, milk, and extract.
Bake in the 15cm tin for 35 minutes at 180°C, then cool and chill.
Prepare three separate chocolate cake batters: dark, milk, and white chocolate.
Marble the three mixtures into the 20cm and 28cm tins and bake for 35-50 minutes at 180°C.
Melt butter, sugar, and syrup for gingerbread and mix into dry ingredients with an egg yolk.
Chill gingerbread dough for 30 minutes, then cut into squirrel, leaf, and acorn shapes.
Bake gingerbread pieces for 10 minutes at 180°C.
Make ganache by heating 600ml cream and stirring in 600g chopped chocolate and extracts.
Prepare hazelnut buttercream by beating 500g butter with 1kg icing sugar, milk, and ground nuts.
Paint real leaves with melted chocolate to create edible decorations.
Assemble the bottom two tiers with buttercream and ganache to look like bark.
Cut squirrel shape from almond cake and replace with a blended cake and nut mixture.
Stack tiers using dowels and cover with chocolate hazelnut spread.
Decorate with chocolate leaves, gingerbread squirrels, and assorted nuts.