I've recently begun experimenting with home-made ice creams, beginning with recipe's from Jenni Britton Bauer's book and more recently branching out into some no-churn recipes. One thing I'd like to be able to do is to use an add-in that provides a good sharp crunch when the ice cream is eaten. I'm looking for something that is a fairly small particle size, say 1/8 to 3/8 inch diameter, and something that I can add to the ice cream either during churning for a churned ice cream or before freezing in a no-churn recipe. The trick is finding something that will not become soft or soggy as a result of absorbing moisture from the mix. The other restriction that complicates my search is that my son has a nut allergy so I'm trying to avoid nuts. Besides, nuts provide a more dull crunch that is not really the sharp crunch I'm looking for.
So far I've tried crushed meringue candy, crushed biscotti, crushed Oatmeal Squares cereal, and Honey Bunches of Oats granola. The meringues, somewhat against my expectation, didn't dissolve, and remained pretty well intact in the final product, but their crunch just doesn't provide enough resistance when surrounded by ice cream. All of the other add-ins got soft.
I'm aware that all kinds of options (including those I've tried) exist for ice cream toppings, added after freezing and prior to serving. But I want these crunchy bits dispersed throughout the ice cream, not just on top.
I have a few other candidates to try: Crushed Oreo cookies seem to work in "cookies and cream" recipes. I plan to try this, but in a lot of cases I'd prefer something I could flavor in different directions. I'm thinking about Grape Nuts cereal, which seems to retain crunchiness in milk longer than some cereals. It also occurs to me that a hard toffee, broken up, might work.
So what do you experts think? Anyone have experience with this or other suggestions?