Illustration of the main steps of our pipeline to process direct spectroscopic observations of exoplanets with ERIS/SPIFFIER. A single frame through the pipeline from raw detector image, calibration by SpyFFIER, to PSF subtraction, and final molecular map after stacking all datacubes (from left to right), for HR 8799 e (top row) and 2MJ0219 b (bottom row). The exoplanet HR 8799 e is mainly visible in slitlets 5, 21, and 22 of the molecular map due to its spatial extent in the smallest FOV of ERIS-SPIFFIER ($0_{\cdot }^{\mathrm{\prime }\mathrm{\prime }}8\times 0_{\cdot }^{\mathrm{\prime }\mathrm{\prime }}8$). 2MJ0219 b is only visible in slitlet 8 as the largest FOV (8″ × 8″) undersamples the PSF. The same stray light as described in Hayoz et al. (2025) is visible in the HR 8799 e data, but not in the 2MJ0219 b data.