What non branded foods are made in the same factory as branded?

[WildFlowerBees]

Weetabix and supermarkets own are made in the same factory. I'm interested to know what other things are made the same but we're paying more for the brand when the product is the same.

Dad had a friend whose dad works at a cake and confectionery factory who manufacture wholesale products for a lot of major food retailers; M&S, CoOp and Asda are the names he's mentioned. You know those little bucket tubs of flapjack, millionaires shortbread etc - they are mostly the same.