Tecnam P2006 Flight Instructor with student reported engine failure while conducting training maneuvers. Flight crew returned to departure airport and conducted a single-engine landing.

Narrative

I launched with a student on an Commercial Multi-Engine Training Flight. We departed ZZZ southbound and proceeded IFR VFR-On-Top to conduct high works per the ACS (Airman Certification Standards). We reached approximately 6;000 ft. MSL; I preformed an anticipated ignition failure on the right engine to evaluate the students ability to secure and restart that respective engine. The engine would not start due to what we believe was a right engine starter failure. We ran the emergency procedure checklist to include activating the emergency battery to attempt to restart the engine; we were unsuccessful. I contacted ZZZ Approach on XXX.X and stated 'Aircraft X [requesting priority handling] single engine over the lake'. Generally; I would not have considered this event critical; however I was aware that we would need to get an IFR clearance with a single engine to return to ZZZ. We were able to maintain altitude if need be. We received Radar Vectors and landed for the visual XX at ZZZ with airport operations waiting for us. There was no further incidents or abnormalities. No injuries occurred and the plane was later returned to service that week with a new starter.