I LOVE blueberry muffins! My grandmother had a very close friend who made the best blueberry muffins I ever tasted. Despite the 50-year age difference I ended up marrying her. Tragically, she was chrwed to death by a pack of pit bulls two years after we were wed. Sure do miss them muffins!!
Id say take your original recipe and change it up! Instead of butter use olive oil. Instead of sugar use Stevia if you want. Use almond flour or flax instead of flour. It may not taste the exact same but it will be close.