  Convergent beam electron diffraction is routinely applied for studying
deformation and local strain in thick crystals by matching the crystal
structure to the observed intensity distributions. Recently, it has been
demonstrated that CBED can be applied for imaging two-dimensional (2D) crystals
where a direct reconstruction is possible and three-dimensional crystal
deformations at a nanometre resolution can be retrieved. Here, we demonstrate
that second-order effects allow for further information to be obtained
regarding stacking arrangements between the crystals. Such effects are
especially pronounced in samples consisting of multiple layers of 2D crystals.
We show, using simulations and experiments, that twisted multilayer samples
exhibit extra modulations of interference fringes in CBED patterns, i. e., a
CBED moir\'e. A simple and robust method for the evaluation of the composition
and the number of layers from a single-shot CBED pattern is demonstrated.
