Overnight Breakfast Bars

Ingredients

• 1 1/4 cups all-purpose flour
• 1 1/2 cups old fashioned oats
• 2 tablespoons flax seed meal (optional)
• 1 teaspoon baking powder
• 1 teaspoon baking soda
• 1/4 teaspoon salt
• 2 teaspoons ground cinnamon
• 1 cup granulated sugar
• 1/2 cup packed light brown sugar
• 2/3 cup butter, softened
• 2 eggs
• 1 1/3 cups buttermilk or 1 1/3 cups plain yogurt
• 2 medium apples, peeled, cored, and chopped
• Topping
• 1 cup chopped walnuts or 1 cup pecans
• 1/2 cup packed light brown sugar
• 1 teaspoon ground cinnamon