  We give a novel definition of gravitational energy for an arbitrary theory of
gravity including quadratic-curvature corrections to Einstein equations. We
focus on the theory in four dimensions, in presence of negative cosmological
constant, and with asymptotically anti-de Sitter (AdS) boundary conditions. As
a first example, we compute the gravitational energy and angular momentum of
Schwarzschild-AdS black holes, for which we obtain results consistent with
previous computations performed using different methods. However, our method
differs qualitatively from other ones in the feature of being intrinsically
non-linear. It relies on the idea of adding to the gravity action topological
invariant terms which suffice to regularize the Noether charges and render the
variational problem well-posed. This is an idea that has been previously
considered in the case of second-order theories, such as general relativity and
which, as shown here, extends to higher-derivative theories. Besides black
holes, we consider other solutions, such as gravitational waves in AdS, for
which we also find results in agreement. This enables us to investigate the
consistency of this approach in the non-Einstein sector of the theory.
