This is my special blueberry muffin recipe that I created over 30 years ago and I like it so much that I have never stopped using it, it has a magnificent flavor and a wonderful texture, the freshness life of this muffin is about 4days but if frozen it will last for months.
The part that I like about this muffin is that it is very versatile, you can use any kind of fruit in it besides blueberries, for example you can use cranberries, raspberries, apples, and if you add some solid pack pumpkin with seasonings you have pumpkin muffins and so on, let your imagination run away with you. OK, here is the recipe. You know that all ingredients should be room temperature.

12 medium eggs
2 teaspoons salt
2 cups oil (not peanut oil)
5? tablespoons baking powder
3? cups sugar
3 cups milk or water
8 cups flour
2 to 3 cups blueberries (frozen or fresh)

In a 5 quart mixing bowl place your eggs, salt, oil, using a paddle mix slowly until blended then add sugar and baking powder, and continue mixing on slow speed then add water or milk and add flour slowly, when all flour is added scrape the sides of the bowl and mix until smooth, remove bowl from mixer and place 2 or 3 cups of blueberries in the mixture and blend in by hand (frozen blueberries preferred) dip out into lined muffin pans.
Bake for 25 to 30 minutes in convection oven and 35 to 40 minutes in regular oven at 350 degree preheated oven. This recipe makes 2 ? dozen large muffins.