Yes you can... its what I did. I did my multi-engine commercial ride first and used a Tecnam twin, then a week later I did my commercial single in a 172SP.
Since the single-engine is essentially an add-on to your already existing commercial rating, the check ride should be no longer than *maybe* an hour of ground and *maybe* an hour of flight. For mine, we went out and did a couple stalls, steep turns, chandelle, lazy 8, steep spiral, and 8's on pylons and came back in for a power off 180 landing and that was it. I think it was like .6 on the hobbs.
And on the ground all we covered were the differences in single-engine and multi-engine systems and a couple more holding out questions that my DPE didn't cover the first time around. Eazy peazy lemon squeezy.