  Quantum interference is typically detected through the dependence of the
interference signal on certain parameters (path length, Aharonov-Bohm flux,
etc.), which can be varied in a controlled manner. The destruction of
interference by a which-path measurement is a paradigmatic manifestation of
quantum effects. Here we report on a novel measurement protocol that realizes
two objectives: (i) certifying that a measured signal is the result of
interference avoiding the need to vary parameters of the underlying
interferometer, and (ii) certifying that the interference signal at hand is of
quantum nature. In particular, it yields a null outcome in the case of
classical interference. Our protocol comprises measurements of
cross-correlations between the readings of which-path weakly coupled detectors
positioned at the respective interferometer's arms and the current in one of
the interferometer's drains. We discuss its implementation with an
experimentally available platform: an electronic Mach-Zehnder interferometer
(MZI) coupled electrostatically to "detectors" (quantum point contacts).
