Grease a 9” by 13” baking pan. Cut bread into 1” – 1 ½” cubes.
In a blender, add the eggs, milk, yogurt, maple syrup, vanilla, ginger, cinnamon and salt, and blend until smooth.
Place half of bread cubes in greased pan in an even layer. Scatter half of blueberries onto bread chunks. Pour half the egg mixture over first layer of bread and blueberries.
Place remaining bread cubes in pan, adjusting them so the layer is fairly even. Scatter the remaining blueberries over the bread. Carefully pour the remaining egg mixture over the bread chunks, pouring a little directly onto all pieces of bread.
Cover and allow to rest in fridge for at least 30 minutes, preferably 2 hours or longer.
Preheat the oven to 375°F. Uncover casserole and place in oven.
Cook for 35 minutes, or until a toothpick inserted in the middle comes out just barely clean.
Allow to cool for at least 15 minutes before serving, with a dusting of powdered sugar, if desired.