That's a great question!
Actually, most foods have both countable and uncountable forms, so that the normal question "Would you like some pizza?" is different in meaning to "Would you like some pizzas?" (mini pizzas or famously greedy guest??). Because one person usually eats just part of a pizza or a cabbage, I'm guessing it makes sense to always use the uncountable form unless you have a more ununusual meaning in mind, e.g. "Do you like cabbages?" being for a question for a farmer or gardener.
This is another great reason to never teach foods as being countable or uncountable. It's much better to teach the differences between "Would you like some apple?" (because I've already cut one up) and "Would you like an apple?" etc, something that is best done through drawing. You can find a worksheet of mine that does that plus adds some speaking by Googling "countable and uncountable foods presentation and speaking"