I'm gonna take a wild stab at this and guess they're gonna taste like chalk.

[It looks god-awful, but he can't let down Chalk Sadie so he picks one up, grimacing.]

Hoooo boy I know I'm gonna regret this one.

[And then he takes a bite out of the chalk doughnut, because of course he does. He instantly makes a 'yak' sound, but battles it down anyway- smiling at Chalk Sadie and offering a thumbs up.]

Hmmmmm. That's good eating. [As an aside to Steven.] Oh god please can we leave?