We revisit and clarify the supersymmetric extension of R+R^2 Starobinsky gravity and its generalization, in view of the renewed interest for these models in cosmology. These models are dual to a "standard Supergravity" coupled to two chiral multiplets in a particular formulation of the theory. The multiplets describe supersymmetric inflationary cosmology, one being the inflaton multiplet(containing the Starobinsky skalaron) while the other is the Goldstino multiplet, giving rise to the De Sitter phase of inflation.