Preheat oven to 375 degrees F.
Peel and chop apples coarsely. Add them to a food processor and pulse until they are diced fine.
Add apples to a bowl with lemon juice, milk, eggs, sugar, vanilla, and butter. Mix well.
Add the oats to a food processor and pulse until a fine dust.
In a separate bowl, mix the dry ingredients of pulsed oats, flour, salt, cinnamon, and baking powder.
Add the wet ingredients to the dry slowly stirring to combine.
Use a non-stick cooking spray to coat your mini muffin cups.
Fill muffin cups 3/4 full with the mixture.
Bake for 10 - 12 minutes or until a toothpick inserted in the center comes out clean.
Allow to cool about 10 minutes.
Brush with the 2 tablespoons of melted butter for the coating.
Add cinnamon and sugar to a bowl.
Put your muffins in the bowl.
Add a lid and shake to coat.