Why do choc chips sink to the bottom?

[Hther]

Choc chip cakes are one thing i just don't get quite right, the chips always sink to the bottom and stick to the paper case?

Why and what canI do aboiut it?

is your mixture too runny? mine don't do this but they used to and I can't remember what I changed lol

when do you add them?

at the end as stated in the recipe book

hmm, maybe put them in with the flour

and don't let the butter/marg be too runny