You can turn any bakery item into delectable French toast by soaking it in an egg and milk mixture, sprinkling cinnamon over the top, and grilling it up on a griddle.
Any Costco bread, like the rustic Italian loaf or stale croissants, can become homemade croutons by cubing and toasting them. This is even easier with an air fryer.
A leftover Costco sheet cake can be used as the base for an ice cream cake. Simply scoop some Costco vanilla ice cream over the top and pop it in the freezer.
Another use for leftover cake (or other pastries) is cake pops. Just mash it up, mix it with frosting until it makes a dough, form them into balls, and freeze them.
You can reimagine Costco Danishes as part of a yogurt and fruit parfait. Simply layer protein-rich yogurt over the pastries and top with fruit, granola, and/or nuts.