I would need to see the rest of the recipe, but sometimes apple sauce works, depending upon the makeup of the rest of the recipe. However, don't sweat 1/4 cup - that's actually only a few tablespoons and when you consider that spread out throughout all of the muffins (I'm assuming the recipe makes a minimum of six) that comes to approximately 1/2 tablespoon each - fairly minimal and not enough to ruin your diet. :9