The electronic transport through quantum dots is extremely sensitive to the electrostatic environment. Such dots, used as single electron transistors (SET), are a useful probe for electronic charging. In this work we report electronic transport measurements via hBN (hexagonal boron nitride) on a graphite-hBN-graphene tunneling device utilizing a few-layer hBN as a tunnel barrier. Graphene is gated via a second hBN flake. We find the graphite-graphene electronic transport to be dominated by tunneling through a dot-like defect in the hBN spacer. The bias-gate stability trace exhibits strong dependence on graphene density at zero magnetic field, demonstrating the utility of the dot as a probe for graphene ground-state density of states. At finite magnetic fields, these traces map the zeroth Landau level of the graphene layer. Finally, at elevated bias the dot also serves as a discrete energy current injector into the graphene layer, thereby providing an additional probe to the excited state spectrum. We suggest this defect-assisted tunneling as a new paradigm for sensitive device-based spectroscopy.