  Motivated by work on the bulk topological proximity effect and the
topological bootstrap, we consider two coupled layers of quantum anomalous Hall
(QAH) insulators with opposite signs of time-reversal breaking, which leads to
a trivial band insulator at half-filling. We study the impact of interactions
in this model within slave rotor theory, which leads to a layer-selective Mott
transition, resulting in a fractionalized quantum anomalous Hall insulator
QAH$^*$ where a Chern band insulator coexists with a chiral spin liquid. We
also compute the edge electron spectral function in the vicinity of the QAH$^*$
phase.
