A cutting element is provided including a substrate having a periphery and an interface surface. An ultra hard material layer is formed over the substrate and interfaces with the interface surface. The interface surface also includes a plurality of spaced apart projections formed inwardly and spaced apart from the periphery and arranged around an annular path, such that each projection includes a convex upper surface defining the projection as viewed in plan view. Each upper surface continuously and smoothly curves in the same direction when viewed along a plane through a diameter of the substrate. Bits incorporating such cutting elements are also provided.