Blueberry Muffins (Second Attempt)

I was not satisfied with last batch so I am determined to bake it again. Plus, I was waiting for my whole wheat bread to rise and had nothing else to do. I searched for light fluffy blueberry muffin recipe and came to this:

http://recipes.sparkpeople.com/recipe-detail.asp?recipe=27551

It is extremely easy.

1 large egg, beat until fluffy.
Add:
2 cups Bisquick baking mix
1/3 cup sugar
2/3 cup milk
=>Stir until just mixed

Add:
1/3 cup frozen blueberries
=>Stir a little bit more

Scoop batter into sprayed muffin pan lined with paper cups. Bake at 375F for 18 minutes or until golden brown.

It's good overall. Much better than before. But I find it a little too dry.

Note: Eggs provide moisture. Use 2 eggs instead of 1 and try beat it until more fluffy. I am also missing the buttery taste of muffins. Maybe can try adding 1 tablespoon butter next batch.