  We propose an extension of the scalaron-Higgs model by a non-minimal coupling
of the Standard Model Higgs boson to the quadratic Ricci scalar resulting in a
Higgs-dependent scalaron mass. The model predicts a successful stage of
effective single-field Starobinsky inflation. It features a multi-field
amplification mechanism leading to a peak in the inflationary power spectrum at
small wavelengths which enhances the production of primordial black holes. The
extended scalaron-Higgs model unifies inflationary cosmology with elementary
particle physics and explains the origin of cold dark matter in terms of
primordial black holes without assuming any new particles.
