I will still be cooking dinner in an hour.

[Alice Chu]

1. I will still be cooking dinner in an hour (at the end of an hour).

1) It means that I am already cooking dinner now, and I will continue cooking until the end of an hour. I will be cooking at the end of an hour and I won’t be finished at that time.

2) Can we use “in an hour’s time” instead of “in an hour” to mean the same thing?

 

[Charlie Bernstein]

1. I will still be cooking dinner in an hour (at the end of an hour).

1) It means that I am already cooking dinner now, and I will continue cooking until the end of an hour. I will be cooking at the end of an hour and I won’t be finished at that time.

That's right.

2) Can we use “in an hour’s time” instead of “in an hour” to mean the same thing?

It's correct but not natural.

It's also natural to say you'll still be cooking dinner an hour from now.