I'm thinking of cooking at 3am
Do you do this normally?
For me, no, but the neighbors might wake up because of the fucking smoke alarm.
Maybe you could disable the smoke alarm until you're done? Otherwise, it's kind of rude to wake them up in the middle of the night.
I really don't care. If they can't focus on work and sleep, they need to be smarter.
Starting a fire at 3am can be dangerous when you are tired. Maybe you can try improving your cooking skills in day time so you no longer burn food.