My recipe has converted a lot of skeptics. This isn't exactly health food, but it's probably considerably closer to what our ancestors enjoyed than the modern stuff.
Amounts can vary wildly.
If you want a dense, fruit-rich cake, you'll need two or three pounds of fruit. Other people like a more cakey texture and can use much less. It's all up to you. Don't put anything in your cake that isn't tasty eaten separately. I find ordinary raisins boring, but you may like them.