Mix oats, baking powder, cinnamon and salt in a large bowl.

In a separate bowl whisk the eggs, add milk, honey and vanilla.

Chop apple in a food processor or grate finely.

Mix apple into wet mixture.

Mix wet mixture into dry ingredients. Mixture will be a bit watery.

Pour into muffin pan and bake for 25 minutes.

Remove from oven and cool in pan for 10 minutes.

Cool further on cooling rack.