Preheat the oven to 180C/350F/ Gas Mark 4.
Put all your dry ingredients (flour(s), sugar, baking powder, baking soda, cinnamon) into a large bowl and give them a whisk. Alternatively, sieve all the ingredients into the bowl. Set it aside.
In a large jug (or another bowl) combine together all your wet ingredients (soya milk, oil and yogurt) and mix them together until incorporated. Set aside.
Peel, core and cut your apples into small chunks.
Add the chopped apples into the bowl with your dry ingredients and mix until they are well covered in flour mixture.
Make a small well in the centre and pour in your wet ingredients. Mix everything in with a spoon or spatula only until incorporated, some lumps are fine. Try not to overmix the batter as it will result in heavier muffins.
Divide the batter between 12 muffin cases and bake in the preheated oven for 20-25 minutes or until skewer inserted into cetre of the muffin comes out clean.
Take the muffins out of the oven and let them cool in the muffin tin for a few minutes before you take them out onto the cooling rack. Prepare cinnamon sugar topping.