The Kitchn has a useful Quick Guide to
Ingredient Substitutions for last-minute kitchen
replacements or "if you're trying to modify a recipe out of
dietary necessity (shifting it to be dairy or gluten-free, for
example)." Find the best gluten-free flour substitute, or what to
replace for cake flour, buttermilk, vinegar, bananas, and much
more. And make sure you read the comments for the complete list of
ideas.
