A thousand times YES! I've never received so much positive feedback on a recipe after people have made different substitutions! You can make these with dairy free Greek yogurt (try coconut) and dairy free milk, with gluten free flour, with a sugar substitute such as stevia, and even with an egg substitute to make them vegan. As already mentioned, you can even replace some of the oil with more yogurt, and reduce the sugar more if you like. If I haven't mentioned the particular substitution that you want to try, I highly recommend browsing through the reader comments below. There's a good chance your substitution has already been tried!