We utilize a particularly sensitive form of electron spin resonance (ESR) called spin dependent recombination (SDR) to observe deep level trap defects at or very near the interface of 6H silicon carbide and the SiO2 gate dielectric in SiC MOSFETs. We find that the SDR response is strongly correlated to SiC/SiO2 interface recombination currents and also find that the magnitude of the SDR response is correlated with processing induced changes in interface trap density, an extremely strong indication that we are observing the dominating interface/near interface trapping defects. The SDR response is extremely large, as large as one part in 350. To the best of our knowledge, this is the largest SDR response ever reported in a semiconductor device at room temperature. This result strongly indicates that SDR will be a powerful tool in exploring deep level defect centers in SiC based devices.