I have a question about the recipe "David Lebovitz's Chocolate Sorbet" from Genius Recipes. Could you use a scraped vanilla bean in this?
To get mileage out of a vanilla bean it really needs to steep: the flavour in vanilla is in the pod, not the seeds themselves.
I think you'd end up with less of a vanilla accent with a bean, but if it's all you have on hand, steep the pod in hot water for 20 minutes or so, then add the sugar/cocoa powder/salt & proceed.
Given the option, I'd stick with extract. Also agree with ChefOno that the seeds may be off-putting for a smooth gelato.