Yes, you can! I know it seems counter-intuitive, and that everything in you is screaming that there is no way these frozen sliders will be anything but a soggy and sad mess. But TRUST ME! If you follow the steps above, you will get delicious make-ahead sliders that turn out golden brown and toasty! I can't explain the magic. (Well, I could, but you didn't come here for a science lesson...) Just trust me on this one. Make a tray and try it out for yourself!