Preheat the oven to 350°F (177°C). Grease a 9x13-inch baking dish.
Whisk the eggs in a large bowl. Then whisk in the applesauce, yogurt, milk, vanilla, and honey. Add the oats, baking soda, and salt, and then stir, with a spatula, to combine. Make sure all of the oats are moistened. Fold in the blueberries.
Pour the mixture into a greased 9x13-inch baking dish.
Bake until the oatmeal is caramelized on top, and a skewer inserted into the center comes out clean -- 45-55 minutes. Cool to room temperature on a wire rack.
When completely cool, cut the baked oatmeal into squares. Enjoy right away or freeze for later. The squares thaw quickly, or they can be reheated briefly in a microwave oven.