Preheat oven to 375°F (190°C). Lightly grease a 13- x 9-inch (3.5 L) metal cake pan.
In large bowl, combine oats, Astro Original Balkan Vanilla yogourt, berries, milk, trail mix, maple syrup, honey, butter, cinnamon and salt, if using; stir gently until coated.
Spread into prepared pan, smoothing top. Bake for 60 to 70 minutes or until oats are al dente and set. Let cool in pan on rack; cut into squares. Serve with a dollop of your favourite Astro yogourt and enjoy!