A single ferromagnetic kagome layer is predicted to realize a Chern insulator with quantized Hall conductance, which upon stacking can become a Weyl semimetal with a large anomalous Hall effect (AHE) and magneto-optical activity. Indeed, in the kagome bilayer material Fe3Sn2, a large AHE was detected. In order to directly probe the responsible band structure features, we measure the optical Hall conductivity spectra in addition to the diagonal optical conductivity over a broad frequency range. Since the former is the energy selective measure of the intrinsic contributions to the AHE, we identify their common origin with the help of momentum- and band-decomposed optical conductivity spectra obtained from first principles calculations. We find that low-energy transitions, tracing "helical volumes"in momentum space reminiscent of the formerly predicted helical nodal lines, substantially contribute to the AHE, which is further increased by contributions from multiple higher-energy interband transitions. Our study also reveals that in this kagome magnet, local Coulomb interactions lead to remarkable band reconstructions near the Fermi level.