Preheat your oven to 400°F (200°C).

In a large mixing bowl, combine the Kodiak Cakes mix and ground cinnamon, whisking until well blended.

In another bowl, beat together the eggs, milk, and vanilla extract until frothy, then fold in the diced apples.

Add the wet mixture to the dry ingredients and gently fold together until combined.

Distribute the batter into muffin cups, filling each about three-quarters full.

Bake for 15-20 minutes until the muffins spring back when touched and a toothpick comes out clean.

Cool in the tin for 5 minutes, then transfer to a wire rack to cool completely.