  Heavy quarks created in heavy-ion collisions serve as an excellent probe of
the produced quark-gluon plasma (QGP). The radiation pattern of jets formed
from heavy quarks as they traverse the QGP exhibits a particularly interesting
structure due to the interplay of two competing effects: the suppression of
small-angle radiation, also known as the ``dead-cone'' effect, and the
enhancement of emitted gluons by medium-induced radiation. In this Letter, we
propose a new observable, based on the energy correlator approach to jet
substructure, which will allow us to disentangle the two scales associated to
these two phenomena and to determine under which conditions the dead-cone is
filled by medium-induced radiation. Combined with the forthcoming
high-statistics measurements of heavy-flavor jets, this work provides a novel
tool to unravel the dynamics of the QGP.
