Preheat oven to 180oC (fan-forced) and grease a 12 hole muffin tin with melted butter.
Sift together the dry ingredients in a large bowl. In a separate bowl, combine the egg, milk and melted butter and whisk until combined. Add the wet ingredients to the dry ingredients and fold together until just combined.
Divide only two-thirds of the mixture amongst the 12 tins. Gently spoon over a small amount of chocolate spread on each and then cover with remaining mixture.
Bake for 10 minutes or until golden and cooked through. Allow to cook in pan.
For the coating, combine the sugar and cinnamon. Brush each donut with the melted butter and then coat in the sugar. Serve.