Preheat the oven to 170°C/Gas Mark 3. Line a 12-hole muffin tin with paper muffin cases.
Sieve the flour and mixed spice into a large bowl.
Mix together the courgette and carrot with all of the Opies Stem Ginger and reserved syrup.
In a large mixing jug, combine the eggs, oil and sugar. Pour the liquid mixture into the flour and combine well using a wooden spoon. Fold in the grated vegetables and walnut pieces.
Divide equally between the muffin cases and bake for about 25 minutes until risen and firm to the touch. Leave to cool. Mix the icing sugar with the remaining syrup and drizzle over the tops of the muffins.
Mix the icing sugar with the remaining syrup and drizzle over the tops of the muffins.