  We present a reproduction of the Planck 2018 angular power spectra at $\ell >
30$, and associated covariance matrices, for intensity and polarization maps at
100, 143 and 217 GHz. This uses a new, publicly available, pipeline that is
part of the PSpipe package. As a test case we use the same input maps,
ancillary products, and analysis choices as in the Planck 2018 analysis, and
find that we can reproduce the spectra to 0.1$\sigma$ precision, and the
covariance matrices to 10%. We show that cosmological parameters estimated from
our re-derived products agree with the public Planck products to 0.1$\sigma$,
providing an independent cross-check of the Planck team's analysis. Going
forward, the publicly-available code can be easily adapted to use alternative
input maps, data selections and analysis choices, for future optimal analysis
of Planck data with new ground-based Cosmic Microwave Background data.
