Lemon zest adds a pop to these blueberry, brown sugar, and oatmeal squares. They’re perfect for breakfast, dessert, or a quick snack.
- 3 cups fresh blueberries
- 1/2 cup granulated sugar
- 1 teaspoon vanilla extract
- 3 tablespoons lemon juice (from about 1 large)
- 4 teaspoons cornstarch
- 2 tablespoons cold water
- 2 1/2 cups rolled oats
- 1 1/4 cups all-purpose flour
- 3/4 cup packed light brown sugar
- 1 tablespoon lemon zest (from about 1 large)
- 1/4 teaspoon coarse salt
- 1 1/4 teaspoons ground cinnamon
- 2 sticks (1 cup) cold unsalted butter, cubed
- Preheat the oven to 350°F. Line an 8-inch square cake pan with parchment paper to create a sling for easy removal. Spray with non-stick cooking spray.
- In a medium saucepot over medium-high heat, add the blueberries, granulated sugar, vanilla, and lemon juice. Stir to combine. When the blueberries begin to release their juices, allow the liquid to come to a boil. Reduce the heat to medium-low and simmer, stirring occasionally, until the berries are broken down and tender, about 10 minutes.
- While the blueberries are cooking, whisk the cornstarch with the water until blended in a small bowl. Gradually stir the cornstarch slurry into the blueberry mixture and continue stirring until the mixture is visibly thickened, about 1 minute. Remove pot from heat. Transfer the blueberry mixture to a bowl and cool to room temperature on the counter. Then refrigerate until chilled, about 1 hour.
- In a large mixing bowl, stir the oats, flour, brown sugar, lemon zest, salt, and cinnamon together until combined. Using a pastry blender (or two butter knives), cut in the butter until the mixture has the texture of coarse crumbs.
- Firmly press half of the crumbs into the bottom of the prepared pan to create a smooth, even layer. Top with the blueberry filing, and then scatter the remaining oat mixture on top. Press down lightly to make sure it adheres.
- Bake until the edges are set and the top layer of crumbs is a light golden color, about 50-55 minutes. Remove from the oven and place on a wire rack.
- Cool completely in the pan, about 1 hour at room temperature, and then use the ends of the parchment paper to help lift the bars out of the pan. Slice into even squares and serve.
- Store leftover blueberry squares in an airtight container in the fridge for up to 1 week.
- Prep Time: 25 minutes
- Cook Time: 1 hour, 5 minutes
- Category: Bars
- Method: Stovetop/Baking
- Cuisine: Snacks
Keywords: blueberry, oat, oatmeal, squares, bars