In 1956, the pioneering experiment of Hanbury Brown and Twiss (HBT) on measuring the sizes of bright stars was limited by the time resolution of their detectors and their telescope size. Recent developments in single-photon avalanche diodes (SPADs) have lowered detector time resolution to under tens of picoseconds. In this work, we report the results of laboratory tests of SPAD detectors to observe the HBT effect in photon-counting mode. Using a simple laboratory setup and cutting-edge SPAD detectors, we obtain a time resolution of ≈ 20ps (2 SPADs + TDC). Additionally, using thermal light sources and narrow spectral filters, we analyze the second-order correlation function obtained from different light sources of continuous and line spectra. Results are discussed and compared with the expectations. Furthermore, we report on a setup, allowing to simulate and estimate the size of an artificial star of known size to verify the analysis and data correlation techniques.