If you don’t count inactive time, overnight oats are great. I like to microwave some milk with some kind of fruit, then dump in some quick-cooking oats and refrigerate it overnight. My little one loves it!

Fruits and vegetables if your kids will eat them are obviously the best choice, but I realize that’s a big “if”.

Chicken nuggets can be microwaved in about a minute. Some brands make cauliflower-chicken nuggets.

Plain rice balls aren’t exactly quick, but if you make them ahead of time they refrigerate okay and can be a good snack. Personally I don’t like the texture once they’ve been chilled but they’re a big hit with my kid.

Cheese (sticks or cubes) take very little time to prepare.

(Edit: i didn’t realize this post was this old until after I’d finished. Oops.)