Hadron spectroscopy provides direct physical measurements that shed light on the nonperturbative behavior of quantum chromodynamics (QCD). In particular, various exotic hadrons such as the newly observed T + cc by the LHCb collaboration, offer unique insights on the QCD dynamics in hadron structures. In this letter, we demonstrate how heavy ion collisions can serve as a powerful venue for hadron spectroscopy study of doubly charmed exotic hadrons by virtue of the extremely charm-rich environment created in such collisions. The yields of T + cc as well as its potential isospin partners are computed within the molecular picture for Pb-Pb collisions at center-of-mass energy 2.76 TeV. We find about three-order-of-magnitude enhancement in the production of T + cc in Pb-Pb collisions as compared with the yield in proton-proton collisions, with a moderately smaller enhancement in the yields of the isospin partners T 0 cc and T ++ cc . The T + cc yield is comparable to that of the X(3872) in the most central collisions while shows a considerably stronger decrease toward peripheral collisions, due to a "threshold" effect of the required double charm quarks for T + cc . Final results for their rapidity and transverse momentum pT dependence as well as the elliptic flow coefficient are reported and can be tested by future experimental measurements.