I have been playing with Cook and have created some small projects. I decided to delete two of them but they don't get deleted from the sandbox. Is this intentional or did I do something wrong?

Everything is normal.


Sandbox is not a bridge with the builder !

It is an area wher you can install for real your generated component.

So, if you make some changes in the builder, you must regenerate your project for the sandbox.
If you delete your project, it is still installed in the sandbox, until we flush it.