  The modification of the hard core of jets in a dense QCD medium is studied.
In particular, we consider partons which possess a virtuality somewhat larger
than the multiple scattering scale of the medium ($\hat{q} \tau$, where
$\hat{q}$ is the transverse broadening jet transport coefficient, and $\tau$ is
the formation length of a particular emission). We delineate the region of
parameter space where the higher-twist approach is applicable, and derive the
in-medium DGLAP evolution equation. We study a region in parameter space where
this is the dominant mechanism of energy loss. We argue that such a regime is
pervasive in most cases of jets in $A$-$A$ and future $e$-$A$ collisions, and
controls the modification of the hard core of jets and the leading single
particle spectrum at high transverse momentum ($p_\mathrm{T}$).
