- Preheat the oven to 180°C/gas mark 4. Line a 12-cup muffin tin with paper cases and set aside.
- Place the spinach in a food processor with the eggs, lemon juice and vanilla and blend until as smooth as possible. With the machine running, slowly pour the oil in through the top until it has all been incorporated. Add the flour, sugar and baking soda and blend again to create a smooth, thick batter. Pour into a large bowl and stir in the courgette.
- Divide the batter evenly amongst the paper cases until they are three-quarters full. Bake in the oven for 20 minutes, until the cupcakes are very lightly golden on top and springy to the touch. Remove and leave on a wire rack until completely cool.
- Meanwhile, to make the buttercream, discard the avocado skin and stones and place the flesh in the food processor. Add the butter and blitz until well blended. Add the icing sugar and blitz again until completely smooth and fluffy.
- Spread an equal amount of buttercream on each cooled cupcake with a small knife. Decorate the tops with a sprinkling of pomegranate seeds or a raspberry on each one. Arrange on a platter or cake stand to serve.
TIP - For a more chocolately finish, use 50g of cocoa powder and 200g of self-raising flour in the cupcakes (instead of 250g flour) and use 2 tablespoons of cocoa powder in the buttercream topping.
*Refer to Coeliac Society Food List for certified gluten free products