Line your tin(s) with baking paper. No need to do this if you are using the foil trays, but you may wish to lightly grease with butter or oil.
Preheat oven to 130C/270F if you have a fan oven, 150C/300F if not a fan oven, or gas mark 2.
In a large pan over a low heat, melt together the golden syrup, black treacle, butter and sugar. Don't boil it - keep stirring regularly until the sugar is dissolved.
In a very large mixing bowl, sift together the flour, bicarbonate of soda and the ground ginger.
In a jug, whisk the eggs into the milk.
Chuck everything into the bowl together, don't forget the oats, and stir with a hand whisk until combined.
Pour evenly into the baking tin(s), top with the ginger pieces and bake for approx 45 mins - 1 hour.
It's ready when it feels firm and dry when you press on it. If the top is glistening, it needs a little longer.
Leave to cool completely in the tin. Wrap in cling film and don't touch it for a whole week.
Slice it up, freeze what you need to, serve with a strong mug of Yorkshire Tea.
