Cut the butter into cubes and leave at room temperature to soften.
Finely chop the stem ginger.
Finely chop the crystallised ginger.
Fit the K beater to the machine.
Line the round tin with parchment paper.
Pre heat the oven to 160°C.
Add Ingredients 1 (bicarbonate of soda, ginger, cinnamon, flour, spice, baking powder) into the Mixer bowl.
Attach the Mixer bowl to the machine and fit the splash guard.
Mix on speed 2 for 10 seconds.
Add the first 4 items of Ingredients 2 (butter, sugar, treacle, syrup) to a saucepan.
Heat on a medium high heat until melted, stirring frequently.
Transfer the contents of the saucepan to the Mixer bowl.
Add the remaining items of Ingredients 2 (milk, egg).
Mix on speed 4 for 1 minute.
Scrape down the bowl.
Add Ingredients 3 (stem ginger, crystallised ginger) into the Mixer bowl.
Mix on speed 4 for 30 seconds.
Transfer the contents of the Mixer bowl into the round tin.
Bake for 1 hour at 160°C.
Leave to cool.
Add Ingredients 4 (water, sugar, syrup, cinnamon) to a saucepan.
Heat until boiling then reduce to a medium high heat.
Simmer until thickened for about 5 minutes.
Invert the cake onto a wire rack, ensuring the base now becomes the top.
Pour the syrup over the top and sides of the cake.
Serve.