Start by melting the butter, brown sugar, corn syrup, molasses, cinnamon, and ginger together. I was afraid of burning the sugar so I did this over pretty low heat.
Then remove the melty sugar mixture from the heat and mix in the eggs, milk and baking soda.
Put the flour in a bowl and pour the liquid ingredients in, mix well. Like Nigella says, it will be a VERY liquid batter, thus making it a bit difficult to mix well, I had to use a whisk to get the lumps out.
Pour into a foil lined pan.
Bake for about an hour, until it is firm in the middle.
Once the gingerbread is cool you can make the icing, I had to double the icing recipe and didn't use any water, it was the right consistency with just the lemon juice and powdered sugar. Once the icing is set cut into squares, like the ones on the middle tier.
Gingerbread with Lemon Icing from How to be a Domestic Goddess by Nigella Lawson
1/2 c. plus 2 T butter
1/2 c. plus 2 T brown sugar
3/4 c. plus 1 T corn syrup
3/4 c. plus 1 T molasses
2 t fresh ginger, grated
1 t cinnamon
1c. plus 2 T milk
2 lg eggs, beaten
1 t baking soda, dissolved in 2 T warm watter
2 c. flour
Icing: 2 T lemon juice
1 c. plus 4 T powdered sugar, sifted
Preheat oven to 325
In a saucepan, melt the first 6 ingredients together over low heat.
Remove from the heat and mix in the milk, baking soda and eggs.
Pour over the flour and mix well, it will be very wet.
Pour into a foil lined 12x8 pan and bake for 45 min to an hour until risen and firm.
Let cool, then make the icing by whisking together the sugar and lemon juice, if needed thin with a bit of warm water.
Spread the icing over the gingerbread, let it set, and cut into squares.