I didn't have a 15x10 pan, so I used 2 - 13x9's. Worked great & still made 48 bars (about 2x2). Were ready in exactly 20 minutes. I used egg substitute, fat free milk, light country crock & reduced fat cream cheese (would have used fat free, but the store didn't carry it). My friend asked me to make them again for Thanksgiving. We loved them! Would really be great if you're going 2 places in the same day, you bake once.