A cutting element for a drill bit can include a first layer of polycrystalline diamond, a second layer of polycrystalline diamond, wherein a boundary between the first layer and the second layer is nonplanar, and a substrate. The first and second layers can be formed from polycrystalline diamond of different grain sizes. One of the first and second layers can be leached of a catalyzing material. The first layer can be formed on a first substrate having a nonplanar surface feature, removed from the first substrate, and placed over the second layer to form the nonplanar boundary. The first layer can be leached of a catalyzing material prior to being applied to the second layer. A barrier layer can be placed between the first layer and the second layer to prevent sweeping of a catalyzing material into the leached first layer.