Place half of bread cubes in a greased dish...sprinkle with blueberries (only use half). In a mixing bowl, beat eggs, cream cheese, yogurt, sour cream, cinnamon, vanilla, and sugar. Pour mixture over top and sprinkle the rest of blueberries on top. Cover and refrigerate over night. Bake at 350 degrees uncovered for 20-25 minutes. Cut into squares and serve with syrup or powdered sugar.