• Preheat oven to 350F / 180C. Grease or line a muffin tray.
• Peel and finely grate the parsnips. Set aside.
• Use an electric mixer to beat the butter and sugar together in a large mixing bowl until light and fluffy.
• Add the eggs one at a time, beating each in well.
• Beat in the zest, lemon juice and vanilla extract, blend well and then add the yogurt and combine.
• Sift in the flour, baking powder, bicarb of soda and salt and stir in the poppy seeds and parsnip. Combine it all thoroughly, but don't overbeat it.
• Spoon the mixture into the muffin cups, filling them ¾ full.
• Bake for 20 minutes or until an inserted skewer comes out clean.
• Allow to cook for a few minutes in the muffin tray and then transfer to a wire rack to cool completely.

For the drizzle topping:

• Stir lemon juice, teaspoon by teaspoon, into the icing sugar until a runny consistency. Drizzle over the completely cooled muffins.