When we were there a few weeks ago, we asked about this. We were told that we had to find out about it at our resort. I think we were at Goofy's when we asked. You might be able to ask at a reg. CS place. Goofy's would not let us convert CS credits into snacks.

Back at CSR, Cafe Ris let us convert our remaining CS credits to snack credits (3 snacks per CS) for things to take home, but only on our last day right before we left for the ME bus.

Maybe you'll have better luck than us. At least we did get to bring home some Rice crispie treats and such.