Preheat oven to 350 degrees F (180 degrees C). Grease an 8 inch square dish. Combine Quick Cooking Oats (1 cup) and Water (2/3 cup) and let stand for about 5 minutes.
Cream together Unsalted Butter (1/4 cup), Granulated Sugar (1/4 cup) and Brown Sugar (1/2 cup) using a handheld mixer for about 2 minutes.
Whisk All-Purpose Flour (3/4 cup), Ground Cinnamon (1/2 teaspoon), Baking Powder (1/2 teaspoon), Baking Soda (1/2 teaspoon) and Salt (3/4 teaspoon) in a small bowl.
Add Egg (1) and Vanilla Extract (1 teaspoon) and beat until combined. Add flour and oat mixtures and mix until combined. Gently fold in half of the Fresh Mixed Berries (2 cup).
Spread the batter in dish and sprinkle with some more sugar and oats. Scatter remaining berries evenly over top.
Bake 40-50 minutes. Let cool on a wire rack, then serve!