In a large bowl, whisk together the dry ingredients until they are well combined. Next, add the applesauce, milk, vinegar, maple syrup, and two tablespoons of oil. Mix throughly.
Divide the donut batter into the donut baking pan. If you don't have one, use a cupcake pan. Do not fill the molds to the top; leave space for the topping.
To prepare the mixture, take a small bowl and combine the chopped apple, chopped walnuts, sugar, cinnamon, and clove.
Add a tablespoon of the apple topping to each doughnut and press it down a bit.
Place in the oven for about 20 minutes or until you insert a toothpick and it comes out clean.
Notes
If you don't have a doughnut pan, use a muffin pan.
Store in an airtight container in the pantry or other cool place when they are at room temperature.