Grease and line a 20cm round cake tin.

Pre-heat the oven to 160C (320F) fan-forced.

Place the butter and sugar in the bowl of a food processor and whiz them together until they are combined and light.

Scrape the sides down into the bowl then add the eggs, vanilla, passionfruit and strawberries.

Whiz until everything is well combined.

Scrape down the sides again and then with the motor running, add the flour one tablespoon at a time until you have added 4 then slowly add the rest of the flour.

Blitz it just until the flour is mixed in. Don't over-beat it.

Spread the batter into the cake tin.

Bake for 50 minutes to 1 hour or until a cake tester inserted in the middle comes out clean.

Leave to rest in the tin for 5 minutes and then transfer to a wire rack to cool completely.

Meanwhile make the icing.

In the bowl of an electric mixer, beat the butter until soft then add the icing sugar.

Mix until the icing sugar is no longer powdery then add the yoghurt and half the passionfruit. Continue to mix until it is light and fluffy and a spreadable consistency.

Place ¼ of a cup of icing sugar on a plate. Pick up the cake with one hand on the bottom and one on the top and roll the sides in the icing sugar, pressing down to make it stick.

Shake off any excess and place the cake on a serving platter.

Spread the icing over the top and drizzle with the remaining passionfruit.

Serve at room temperature.