Preheat the oven to 180°C/350°F. Grease and line a 12-hole muffin tin with paper liners.
In a large mixing bowl, whisk together the flours, baking powder, salt and spices.
In a separate bowl or mixing jug, combine the brown sugar, oil, yogurt, eggs and vanilla. Whisk until well combined then pour the wet ingredients into the dry ingredients. Mix well.
Fold in the chopped apples.
Mix together the cinnamon and sugar if using.
Divide the batter between the muffin cups then place in the oven. Sprinkle a little cinnamon sugar on top of each muffin.
Allow the muffins to bake for 15-20 minutes or until a toothpick inserted comes out clean.
While the muffins are baking, mix together the butter and honey.
When the muffins are baked, remove from the oven and allow to cool for 10-15 minutes before serving with the honey butter.