01 - Preheat oven to 350°F. Generously grease a 9x9-inch baking dish with butter.
02 - Whisk cottage cheese, eggs, milk, maple syrup, vanilla, and melted butter in large bowl until smooth.
03 - Stir rolled oats, baking powder, cinnamon, and salt together in separate bowl.
04 - Pour dry ingredients into wet mixture. Stir until just combined.
05 - Gently fold blueberries into batter.
06 - Pour mixture into prepared baking dish. Smooth top with spatula.
07 - Sprinkle almonds or walnuts and coarse sugar evenly over top if using.
08 - Bake 35 to 40 minutes until center is set and top is golden brown.
09 - Let cool 10 minutes before slicing. Serve warm or at room temperature.