Step 1

Preheat oven to 180°C. Grease and line the base and side of a 20cm (base measurement) springform pan. Combine sour cream, lime rind and 2 tablespoons lime juice in a bowl.

Step 2

Use an electric beater to beat butter, vanilla and 100g (1/2 cup) sugar in a bowl until pale and creamy. Add eggs, 1 at a time, beating well after each addition. Stir in sour cream mixture and combined flour, in alternating batches. Spoon into pan. Bake for 35-40 minutes or until a skewer inserted into centre comes out clean. Cool in pan for 15 minutes.

Step 3

Meanwhile, stir the water and remaining sugar in a saucepan over low heat for 2-3 minutes or until sugar dissolves. Bring to the boil. Simmer for 10-12 minutes, brushing down side of pan occasionally with a wet pastry brush, or until golden. Remove from heat. Carefully add lime slices and remaining lime juice. Swirl to combine. Cool for 2-3 minutes.

Step 4

Transfer cake to a wire rack over a lined tray. Spoon over hot syrup and lime slices.