If you have a favorite recipe or brand that's a little expensive, take a look at Top Secret Recipes. FYI recipes/list of ingredients cannot be copyrighted (but the directions might be).
One product I love but cannot find very often is No Pudge Brownies (the recipe is on the Top Secret Recipe site). To make the brownies more nutritious and high in protein, instead of adding any liquid/vanilla yogurt, drain a can of black beans, rinse then return to the can and fill with water. Put beans and water in a blender until smooth, then add to dried mix and bake as directed - delicious.