- 1 cup whole oats
 - 1 cup oat flour
 - 1 teaspoon ground cinnamon
 - 1/2 teaspoon allspice
 - 1/2 teaspoon baking soda
 - 1/2 teaspoon salt
 - 2 large apples – peeled, cored, and chopped
 - 3/4 cup plain yogurt
 - 2 eggs
 - 1/2 cup brown sugar
 - 1/4 cup butter, melted
 - 1 teaspoon vanilla extract
 - 1/2 cup chopped walnuts
 
- Preheat oven to 350 degrees F (175 degrees C). Generously grease muffin cups or line with paper liners.
 - Combine oats, oat flour, cinnamon, allspice, baking soda, and salt in a large bowl. Add apples, yogurt, eggs, brown sugar, butter, and vanilla extract to oat mixture until batter is well mixed; fold in walnuts. Pour batter into the prepared muffin cups.
 - Bake in the preheated oven until a toothpick inserted in the center comes out clean, about 25 minutes.