Preheat the oven to 170C (340CF). Place walnuts on a baking tray and bake for 10 minutes or until golden brown. Set aside.

Turn oven up to 220C (or 425F) and generously grease a 12 cup muffin baking pan with butter or oil (or use paper cups).

In a large bowl, sift the flour, baking powder, baking soda, salt and cinnamon together and whisk well to combine. Set aside.

In a medium bowl, combine the oil with the sugars, yoghurt, extract and whisk well. Add the eggs and whisk again until well combined.

Take 1 tablespoon of the dry mixture and place in a smaller bowl and stir through apples and walnuts until they are well coated in the flour mixture (this helps evenly distribute the apple and walnut pieces throughout the mixture and prevents them from sinking to the bottom of the muffins).

Make a well in the center of the dry mixture and add the wet ingredients. Gently fold the mixture until just combined (about 9 folds) and then gently fold the apples and walnuts in until just incorporated.

Evenly divide the batter into the 12 muffin cups, making sure that the mixture is topped to the brim (tip: using an ice cream scoop can help ensure even amounts of mixture in each muffin cup).

Bake for 5 minutes at 220C (425F), then reduce the heat to 190C (375F) and bake for another 15 minutes or until a toothpick inserted into the center comes out clean.