seems to me that means undertaking that training for 2 hours rather than, for example, doing two flights of an hour each where such training was undertaken? If I do such a one hour flight from where I am based I would spend about 25 minutes max doing the stall/spin avoidance exercises.
There is no stipulation as to how many flights to accrue 2 hours and nor should there be, The old way was perhaps too restricted and based on 'Pavlov's Dog'. Much time was spent in repetition honing a valuable, in itself, auto response. The aircraft can be stalled in any phase of flight of course and therefore there is no need to climb to straight and level before training commences. Much can be done more than only 25 minutes in level flight: the departure and the the climb, climbing turns, slow flight including simulated poor visibility, during the descent, the circuit and the approach. The two hours can be fully utilised with a little imagination even, have you thought, whilst taxying. Interestingly, some years ago, the UK General Aviation Safety Council (GASCo) produced a study of all this and to which I contributed. The most noted phase for loss of control, resulting in a fatality, was during the climbing turn following the take-off, but this is ignored and rarely mentioned - take note.