These crackers aren't exactly like Goldfish, but they've got a nice crunch and cheesy flavor. Unfortunately I didn't have a teeny-tiny fish-shaped cookie cutter so I cut them into squares and rectangles.
'cheese crackers' on Serious Eats
Use cheese with a lot of flavor. Aged cheddar instead of a mild one, for instance. Any cheese you can grate will be fine: Parmesan, Swiss, Romano, or any others you like. For a softer cheese, I used Limburger. You could also use a soft blue cheese, goat cheese, or even a Camembert. Or a combination of what's left in your cheese drawer.