Easter cake mix cookie bars are the easiest spring dessert—made with yellow (or white) cake mix, eggs, oil or melted butter, vanilla, and loaded with pastel Easter M&M’s plus chocolate chips for a soft, chewy, crowd-pleasing treat. Bake in a 9×13 pan until the edges are lightly golden, cool, then slice into bars for Easter parties, potlucks, or a fun weekend bake , save this easy cake mix bar recipe for later!