Whole-Grain Blackberry Spice Muffins

Ingredients

• 2 cups all-purpose flour (replace half with whole wheat flour)
• 1 cup rolled oats
• 1 cup packed brown sugar
• 1 1/2 tsp baking powder
• 1/2 tsp baking soda
• 1/2 tsp salt
• 1/2 tsp apple pie spice mix
• 1 cup skim or 1% milk
• 1 tsp vanilla extract
• 1 large egg, lightly beaten
• 1 1/2 cups blackberries, coarsely chopped
• cooking spray
• 1/4 cup granulated sugar