Mix everything together and once margarine or butter is soft, place in greased square, pyrex small loaf tin. Place in middle of a preheated oven, 180 C / Gas 4. Bake for about 45 minutes or until spongy to the touch. Leave to cool and gently turn out.
Other ideas
You can use soft brown sugar instead of caster sugar, and golden syrup instead of treacle. Cover with a small amount of water and evenly spread then sprinkle with sugar before baking.
It's probably my rubbish baking skills by I really didn't like this. It was dry and crumbly and didn't go all gooey after a couple of days. I didn't really enjoy making it either. Very sorry.