We have developed a full-field optical coherence microscopy system providing intensity-based tomographic images and spectroscopic information with ultrahigh spatial resolution. Local measurements of the backscattered light spectrum center of mass are achieved through short-time Fourier analysis of a stack of en face interferometric images acquired with a Linnik-type microscope. Using a halogen lamp as an illumination source enables us to achieve spectroscopic imaging over a wavelength range from 600 to 900 nm with a spatial resolution of approximately 1 microm. Absorption measurements of a colored gel are reported as a validation of the technique. Enhancement of tissue imaging contrast is demonstrated by imaging a Xenopus Laevis (African frog) tadpole ex vivo.