Identify your use: toast/French toast (soak-friendly) vs stuffing/cubes (even texture) vs sandwiches (slice and spread).
Choose the closest ranked bread: Challah for general purpose, milk bread for the softest crumb, or egg bread for similar richness.
If the substitute is sweeter (panettone), reduce added sugar by about 25–33%; if it’s drier/denser (white sandwich bread), increase soak time.
Cut consistently: cubes or slices of similar size so the substitute soaks and browns evenly.
Taste and adjust after baking: add a small pinch of salt or a tiny splash of dairy to rebalance sweetness and richness.