Measure all ingredients and dice your apples into very small, uniform pieces (approximately 1/4 inch) to ensure they cook evenly.
Preheat your oven to 350°F (175°C) and grease a mini muffin tin or donut hole pan.
In a medium bowl, whisk together the flour, baking powder, salt, cinnamon, nutmeg, and cloves until well combined.
In a separate larger bowl, whisk together sugar and eggs until light and slightly fluffy (about 1 minute of whisking).
Add the melted butter, milk, and vanilla extract to the egg mixture, then whisk until smooth.
Gradually add the dry ingredients to the wet ingredients, stirring gently just until combined. Avoid overmixing.
Fold in the diced apples gently.
Use a tablespoon or small cookie scoop to portion the batter, filling each cavity about 3/4 full.
Bake for 10-12 minutes, or until a toothpick inserted comes out clean.
While the donut holes are baking, melt butter in one small bowl. In another bowl, combine sugar, cinnamon, and crushed graham crackers for the coating.
Allow the donut holes to cool just enough to handle (about 5 minutes).
Dip each donut hole in melted butter, then roll in the cinnamon-sugar-graham mixture until completely coated.
Serve warm or at room temperature.