Preheat the oven to 200°C/gas mark 6. Brush a six-hole doughnut pan with some of the melted butter.
In a large bowl, combine the flour, sugar, baking powder, bicarbonate of soda, salt and the ground spices and make a well in the centre.
In a jug, stir together the milk, egg, melted butter, vanilla and apple cider vinegar. Gradually add the liquid mixture into the well in the middle of the flour and stir. Continue gradually adding the liquid and stir constantly to prevent lumps.
Spoon this mixture into a piping bag and pipe each doughnut hole two thirds full. Bake for 10-12 minutes or until risen and golden. Meanwhile, stir together the ingredients for the glaze until smooth.
Once the doughnuts have finished baking, place them on a wire rack to cool, around 15 minutes. Once cool, dip the doughnuts in the icing and place back on the wire rack, then spray them with the gold glitter. Leave to firm up.