Preheat the oven to 375.

In a large bowl, combine the oats, baking powder, cinnamon and salt.

In a medium bowl, whisk together the egg, milk, Greek yogurt, applesauce, maple syrup, melted butter and vanilla until smooth.

Add the wet ingredients to the dry ingredients and mix well. Carefully fold in the blueberries (so you don’t break and burst them).

Transfer the batter to a well greased 8x8 pan. It will be very full and liquidy.

Bake at 375 for about 35 minutes, until the edges are browned and the middle is set.

Let cool 5-10 minutes before slicing. (It needs a few minutes to set up so the baked oatmeal squares aren’t crumbly when you cut them.)

Store, covered, at room temperature for up to 2 days. After that, these are best stored in the refrigerator so they don’t get soggy. (They freeze great, too.)