Step 1

Preheat oven to 160C/140C fan-forced. Line 4 large baking trays with baking paper.

Step 2

Combine flour, sugar and baking powder in a bowl. Make a well. Add melted butter, sour cream, egg, lemon rind and juice. Mix well to combine (mixture will resemble a thick cake batter). Drop level tablespoons of mixture, 6cm apart, onto prepared trays. Bake, 1 tray at a time, for 12 minutes or until just firm to touch. Stand for 5 minutes. Transfer to a wire rack to cool completely.

Step 3

Make Sour Cream Icing: Whisk icing sugar, sour cream and lemon juice together until smooth and thick. Working quickly, spread icing onto biscuits. Sprinkle with lemon zest. Stand for 1 hour to set. Serve.