Blueberry Bars

Bahan-bahan (12 porsi)

• 1 pound (about 4 cups) fresh or frozen blueberries
• ¼ cup brown sugar, tightly-packed
• ¼ cup lemon juice
• 1 ½ tablespoons cornstarch
• 2 ¼ cups old-fashioned oats
• 1 ½ cups all-purpose flour
• ½ cup brown sugar, packed
• ½ teaspoon ground cinnamon
• ½ teaspoon salt
• 1 cup (2 sticks) melted butter