Preheat oven to 350 F (175 C). Spray an 8 inch square baking dish with cooking spray. Set aside.
In a large bowl, combine oats, brown sugar, cinnamon, baking powder, and salt. Set aside.
3 cups rolled oats, 1 cup light brown sugar, 2 teaspoons cinnamon, 2 teaspoons baking powder, 1 teaspoon salt, 2 teaspoons vanilla extract
Add milk, eggs, butter, and vanilla to a blender or medium bowl. Blend or beat on low speed for 30 seconds.
1 cup milk, 2 large eggs, ½ cup unsalted butter, 2 teaspoons vanilla extract
Pour wet ingredients into oat mixture.
Stir in chocolate chips.
¾ cup semi-sweet chocolate chips
Spread mixture into prepared 8 by 8 inch baking pan and bake for 35 to 40 minutes.