Never replicate the code in the comment, then the comment won't be lying when the code changes.

This is a poor example to work off of. You'd probably have something like RECIPE_TEMPERATURE = 350, which you could then tweak to 375 if you needed to...

A more effective example would be

oven.Temp = RECIPE_TEMPERATURE

// we have to wait for the oven to preheat

thread.sleep(time.Minutes * 5)

oven.contents += cookies

Could you make that second line of code into a function preheatOven()? Sure. And your code would be less readable, because you have to break context to go see what the function does... only to find it's one stupid line.

Method names are not comments. They are hints at what the code does. They should not explain why the code is doing it (because the why almost always requires a lot more space than you can fit into a reasonably sized method name).