A new technique of Fourier analysis on a cut sky (Gorski, 1994) has been applied to the two year COBE DMR sky maps. The Bayesian power spectrum estimation results are consistent with the Harrison-Zel'dovich n=1 model. The maximum likelihood estimates of the parameters of the power spectrum of primordial perturbations are n=1.22 (1.02) and Q_{rms-PS}=17 (20) uK including (excluding) the quadrupole anisotropy. The marginal likelihood function on n renders n=1.10 pm 0.32 (0.87 pm 0.36).Comment: 13 pages, 4 figures included, uuencoded Postscript file. Submitted to ApJ Letters, COBE Preprint #94-0