Preheat oven to 180°C (355°F) fan bake. Blitz almonds to a flour in a blender, then sift with the remaining dry ingredients into a bowl. Any almond and coconut bits remaining just pour on top.
Blend wet ingredients excluding zest in a blender, then pour into the dry with the zest, folding until just combined.
Pour into a lined or greased regular muffin tin and bake for 15 minutes, until a skewer in the middle comes out almost dry. Remove cupcakes from tin and cool on a baking rack.
Meanwhile, blend cashews to a flour, then add remaining icing ingredients and blend until smooth. Refrigerate to firm up.
When the cupcakes have cooled, spread a dollop of icing on top of each, and sprinkle with extra lemon zest (and fresh thyme if you want a splash of colour).
Gluten free: Use ½ c brown rice and ½ c buckwheat instead of the spelt.
Nut free: Use ground sunflower seeds in the base instead of almonds. Or just replace with extra flour, but the nuts/seeds give them fat and thus tenderness. For the icing replace cashews with ½ c thick coconut cream, and 1-2 tbsp melted cacao butter to help it hold