Preheat oven to 180 C/ 350 F. Grease and line a 9 inch square cake pan.
Cream together the butter and sugar until light and fluffy.
Beat in the egg until well combined.
Add the golden syrup, treacle and boiling water, and stir well.
Sift over the plain flour, bicarbonate of soda, salt and ground spices.
Stir until well combined (there should be no lumps of flour!).
Pour into the prepared cake pan and bake for 30-35 minutes, or until a skewer inserted in the centre comes out clean.
To prepare the lemon sauce, combine sugar, butter and lemon juice in a small saucepan and bring to the boil over a medium-high heat. Turn the heat down and simmer, stirring constantly, for five minutes, until the sauce thickens. Remove from heat and add the vanilla. Serve over slices of warm gingerbread cake.
This cake also tastes delicious cold, but if both the cake and sauce have cooled, spoon a bit of the sauce over a slice of cake and microwave for 15-20 seconds.
Mum of three, daydream adventurer, OU Life Sciences graduate, occasional crafter, ex-pat Canadian & quite possibly Britain's most northerly food blogger.