We have combined cryogenic scanning probe techniques with laser spectroscopy of single molecules. By scanning a nanocrystal doped with fluorescent molecules through a local inhomogeneous electric field, we have been able to identify and locate two individual molecules that were separated by 12±2 nm. In addition, we have shown that these two molecules were coupled via the coherent dipole-dipole coupling, leading to two sub- and superradiant states. By increasing the intensity of the incident laser beam, we have been able to put into evidence a two-photon transition that takes place at the frequency midway between the original transition frequencies of the system. Furthermore, we have measured the photon statistics of the fluorescence light and shown that when exciting the system at the new frequency we observe photon bunching whereas excitation of the system at any of the original resonances yields photon antibunching. All our observations are verified by comparison with the outcome of calculations based on a master equation approach.