Preheat oven to 325 degrees F. Spray donut pans with nonstick spray.
In a large bowl mix flour, sugar, baking powder, cinnamon and salt together.
In another mixing bowl stir together milk, eggs, vanilla, lemon juice and oil until well combined. Add milk mixture to the flour mixture and stir until mixed well, careful not to over mix the dough.
Gently add in the blueberries to the dough.
Spoon mixture into donut pans, filling them about 2/3 of the way. Bake for 12-14 minutes, or until lightly browned on sides.
Remove from oven and allow to cool. Remove donuts from donut pan and place on wax paper (easy cleanup for the icing below).
For the icing:
Mix sugar, milk and lemon juice in a shallow bowl until smooth. Dip the donuts into the icing, one at a time. Serve and enjoy!