Preheat oven to 400 degrees.

Grease 12 muffin cups or use paper liners.

In large bowl, mix together flour, sugar, salt, and baking powder.

In a separate bowl, mix oil, egg, milk and 1/2 cup applesauce until smooth.

Slowly, add liquid mixture to flour mixture, stirring continuously.

Continue stirring until just moistened. (Note: you might have to add an additional 1/4 cup of applesauce - the batter should be thick, similar to brownie batter).

Gently, fold in blueberries until incorporated.

Spoon the batter into the muffin cups or liners, filling them approximately 2/3 full.

Bake muffins at 400 degrees, until golden brown - approximately 20 minutes.

The muffins are done when a toothpick inserted in the center comes out clean.