200g (plus) of icing sugar (I won't lie, I just spooned it in until I got it to the thickness I wanted)
Instructions
Preheat the oven to 175°C (155°C fan assisted) and grease your doughnut tin.
Mix together the dry ingredients in a large bowl.
Beat the egg with the buttermilk, melted butter and vanilla.
Pour the egg mixture into the dry ingredients, add the lemon rind and mix until just combined.
Divide the mixture in the tin. I did this using an icing bag for neatness, you could easily do it with a spoon too. Fill each ring to about ¾ full. You don't want them rising up and filling the whole in.
Bake for 14-17 minutes, the edges should have started browning and a tooth pick inserted will come out clean.
Remove from the oven and leave to cool in the tin for about 10 minutes before turning out onto a cooling rack.
While they cool, make the glaze. Beat the lemon juice into the icing sugar until smooth and thick. Once the doughnuts are cool enough, dip them in (I double dip) so the top is coated with the glaze. Allowing to set before serving.
Recipe by The Bearded Bakery at http://www.thebeardedbakery.com/baking/cupcakes-muffins/lemon-glazed-oven-baked-doughnuts/