01 - Preheat the oven to 350°F. Generously grease a 9x9-inch baking dish with butter.
02 - In a large bowl, whisk together the cottage cheese, eggs, milk, maple syrup or honey, vanilla extract, and melted butter until the mixture is smooth and well incorporated.
03 - In a separate medium bowl, combine the rolled oats, baking powder, cinnamon, and salt. Stir to ensure even distribution of the leavening agent and spices.
04 - Add the dry ingredients to the wet mixture. Stir gently until just combined, being careful not to overmix which can result in a dense texture.
05 - Gently fold in the blueberries using a spatula, taking care to avoid crushing them, especially if using fresh berries.
06 - Pour the batter into the prepared baking dish. Use a spatula to spread the mixture evenly and smooth the top surface.
07 - Sprinkle the almonds or walnuts and coarse or brown sugar evenly over the top of the batter, if using.
08 - Bake for 35 to 40 minutes, or until the center is set and the top is golden brown. A toothpick inserted into the center should come out clean.
09 - Allow the bake to cool for 10 minutes before slicing into squares. Serve warm or at room temperature.