On Windows Qt Creator 4.5.1:
File / New Project / Non-Qt Project / Plain c++ Application
Build system: cmake
Kit Qt 5.9.3 with MSVC2015
-> main.cpp is added automatically.
But it is not possible to add a new source or header file in the context menu, entry "Add New..." is disabled (gray).
If this is not implemented, maybe change Issue Type from Bug to Suggestion and please consider adding a hint in the status bar for the disabled "Add New" entry