  The interplay between Kondo screening and magnetic interactions is central to
comprehending the intricate phases in heavy-fermion compounds. However, the
role of the itinerant magnetic order, which is driven by the conducting (c)
electrons, has been largely uncharted in the context of heavy-fermion systems
due to the scarcity of material candidates. Here we demonstrate the coexistence
of the coherent Kondo screening and d-orbital ferromagnetism in material system
La$_{1-x}$Ce$_x$Co$_2$As$_2$, through comprehensive thermodynamic and
electrical transport measurements. Additionally, using angle-resolved
photoemission spectroscopy (ARPES), we further observe the f-orbit-dominated
bands near the Fermi level ($E_f$) and signatures of the f-c hybridization
below the magnetic transition temperature, providing strong evidence of Kondo
lattice state in the presence of ferromagnetic order. Remarkably, by changing
the ratio of Ce/La, we observe a substantial enhancement of the anomalous Hall
effect (AHE) in the Kondo lattice regime. The value of the Hall conductivity
quantitatively matches with the first-principle calculation that optimized with
our ARPES results and can be attributed to the large Berry curvature (BC)
density engendered by the topological nodal rings composed of the Ce-4f and
Co-3d orbitals at $E_f$. Our findings point to the realization of a new
platform for exploring correlation-driven topological responses in a novel
Kondo lattice environment.
