Preheat oven to 180 degrees Celsius (350 degrees Fahrenheit).
Place the coconut oil in a large bowl and melt over a saucepan of boiling water or in the microwave.
Add the maple syrup, milk and vanilla and mix well.
Measure out the ground almonds, gluten-free flour and baking powder and mix well.
Add these to the other ingredients and mix well.
Lay out a sheet of greaseproof baking paper on a counter. Sprinkle the surface of the paper and a rolling pin with a generous amount of flour and roll out the cookie dough until about 5mm (¼ inch) thick.
Use a circular cookie cutter to cut shapes out of the dough - you will probably have to roll the dough a few times until you use it all up.
Transfer the cookies onto two baking trays/baking sheets lined with greased baking paper.
Bake in oven for around 10-12 minutes, until golden brown.
They will be slightly soft when you remove them from the oven - leave to cool completely to let them harden before applying the frosting.
For the frosting:
Drain the soaked cashews and add to a food processor or blender with the maple syrup, vanilla and milk.
Whizz until completely smooth, adding more milk or water if necessary.
Split up the frosting into separate bowls if you want to make multiple colours of frosting, and add the cocoa powder, beetroot powder, matcha or spirulina, as desired - add a tiny bit of the powder at a time until you get the desired colour.
Use a knife to spread a bit of frosting over each of the cookies.
Decorate with cacao nibs, desiccated coconut, rose petals or freeze-dried raspberries, as desired.
Taste best when fresh, but keep covered in the fridge for up to a few days.