Preheat your oven to 375°F (190°C). Line your baking sheet with parchment paper and spray it lightly with cooking spray to prevent sticking.
In a large mixing bowl, whisk together the all-purpose flour, white whole wheat flour, granulated sugar, baking powder, baking soda, and kosher salt until well combined.
In a separate bowl, combine the Stonyfield Organic 0% plain yogurt, milk, water, eggs, melted butter, and vanilla extract. Whisk until the mixture is smooth and creamy.
Pour the wet ingredients into the dry ingredients. Gently fold the mixture together with a spatula until just combined. Be careful not to overmix; a few lumps are perfectly fine!
Gently fold in the mixed berries, ensuring they’re evenly distributed throughout the batter.
Pour the batter onto the prepared baking sheet, spreading it out evenly with your spatula. Bake in the preheated oven for about 20-25 minutes, or until the edges are golden and a toothpick inserted into the center comes out clean.
Once baked, remove the sheet pan from the oven and let it cool for a few minutes. Slice the pancakes into squares or rectangles and serve warm with your choice of toppings such as fresh berries, powdered sugar, maple syrup, honey, or yogurt.