Can't go wrong with this one if you need something to take on a packed lunch.
5oz self raising flour
2oz or so of choc chips (to be honest, I just add until it looks right!)
Grease and line a 1lb loaf tin.
Cream butter and sugar together until light and fluffy. Beat in eggs. Sift flour and fold in. Stir in choc chips and bake in centre of oven at 180C (160 fanforced) for 40-45 mins.
Leave to cool before icing. You could ice this with choc fudge frosting.