Preheat the oven to 190ºC/375ºC fan/gas mark 5.
Mix the rice flour, corn flour, sugar and baking powder into a medium mixing bowl and put to one side.
Place the milled flaxseed into a mug and add the boiling water, stir well and leave for five minutes to set.
Whisk the milk, vanilla extract and melted coconut oil in a separate bowl, adding the flaxseeds once it has set.
Pour the wet mixture into the dry ingredients slowly, whisking all the ingredients together until you have a smooth batter, if needed you can add a few extra tablespoons of almond milk.
Grease the donut tin, with melted coconut oil and pipe in the batter (if you don’t have a piping bag, pour batter into a freezer bag and cut the corner off).
Place in the middle of the oven and bake for 12 minutes.
Whilst the doughnuts are baking, make the glaze by preparing a mug of black coffee. Sieve the icing sugar into a mixing bowl and stir in the cooled coffee and mix well.
When the doughnuts are baked, tip them gently out of the tin and place onto a cooling rack.
When cooled, brush on the glaze. Then sprinkle on the freeze-dried strawberries, or sprinkles of your choice. If you do not have any extra sprinkles these doughnuts are delicious just glazed.