hopIQ found 10 beers with the same malty and rich character as Tegernseer Quirinus. Doppelbock, 7.0%, the Tegernseer winter starkbier. Intensely malty with caramel, bread crust and dark fruit; boozy warmth balanced by the brewery's classic clean lager finish. Ranked by flavour match rather than popularity.
Closest match: Pfungstädter St. Nikolaus — 91%. No twin in the catalogue yet.
1 countrymatched across 56 flavour tagsbest match 91%

No beer in the catalogue yet — these come closest.
Close on what matters, with one thing they do differently.
Same idea, less detail — open a beer to see the full comparison.