This provencial masterpiece created by Wendy Kromer alternates layers of lemon curd and vanilla buttercream.
Trim tops of cake layers so they are even. Set one of the layers on a corresponding-size cardboard round and pipe a dam of buttercream around its edge; fill with approximately 2/3 cup lemon curd. Set next cake layer on top, and spread with approximately 3/4 cup buttercream. Place another cake layer on top, pipe a dam of buttercream, and fill with 2/3 cup lemon curd. Set the last cake layer on top, then crumb-coat cake using buttercream. Chill cake layer well, then spread with another layer or two of buttercream to give it a final coat. Decorate tier with candied lemon slices and crystallized lemon-thyme sprigs.