# What You'll Need:
→ Dry Ingredients
01 - 2 cups old-fashioned rolled oats
02 - 1 cup whole wheat flour
03 - 1/2 cup light brown sugar, packed
04 - 1/2 teaspoon baking powder
05 - 1/4 teaspoon ground cinnamon
06 - 1/4 teaspoon salt
→ Wet Ingredients
07 - 1/2 cup unsalted butter, melted and cooled
08 - 1/4 cup plain Greek yogurt
09 - 1 large egg
10 - 1 teaspoon pure vanilla extract
→ Blueberry Mixture
11 - 2 cups fresh blueberries, or frozen thawed and drained
12 - 2 tablespoons granulated sugar
13 - 1 tablespoon cornstarch
14 - 1 tablespoon fresh lemon juice
# Steps to Follow:
01 - Preheat oven to 350°F. Line a 9x9-inch baking pan with parchment paper, allowing overhang on sides for easy removal.
02 - In a large mixing bowl, combine oats, whole wheat flour, brown sugar, baking powder, cinnamon, and salt. Mix thoroughly.
03 - In a separate bowl, whisk together melted butter, Greek yogurt, egg, and vanilla extract until smooth and fully combined.
04 - Pour wet ingredients into dry ingredients and mix until just combined. Reserve 1 cup of this oat mixture for the topping.
05 - Press the remaining oat mixture evenly into the prepared pan to create a compact, even base layer.
06 - In another bowl, toss blueberries with granulated sugar, cornstarch, and lemon juice until evenly coated.
07 - Spread the blueberry mixture evenly over the oat base layer.
08 - Crumble the reserved oat mixture evenly over the blueberries to create a uniform topping.
09 - Bake for 30 to 35 minutes, or until the top is golden brown and the filling is bubbling at the edges.
10 - Allow bars to cool completely in the pan. Lift out using parchment paper overhang, cut into 16 equal bars, and wrap individually if desired.