Honestly, I always recommend microwave first then toast in the oven. The thing with HCCTs is the middle always stay cold or not heated through. So microwaving is best. I say for a minute or so. Then pop into toaster oven on Toast setting to get that crunchy, flaky outside. Keep an eye for when the top starts to get golden, turn off right away since croissants burn easily in home oven. Hope this helps. :)

If you don't wanna put in the oven: 46 seconds in the microwave normally gets the job done 🤷‍♂️

Toaster oven would probably be best, or a convection oven. They will definitely be flat no matter what.

Oven 350... 15min-20 minutes i say top rack, but whatever floats your boat