Do

1. Preheat oven to 160ºC. Grease and flour a 25cm ring tin.

2. Place egg whites and cream of tartar into TM bowl and whip 6 min/Butterfly/50ºC/speed 3/MC off until peaks form. Remove Butterfly, set aside egg mix.

3. Place chocolate and nuts into TM bowl and mill 10 sec/speed 8.

4. Add butter, sugar and vanilla into TM bowl and mix 1 min/speed 4, scraping down sides of bowl if necessary.

5. Add egg yolks one at a time through lid onto rotating blades and incorporate 1 min/speed 4.

6. Add flour and sour cream and mix 20 sec/speed 6.

7. Add the egg whites and mix 3 sec/speed 6. Finish incorporating egg whites with the spatula.

8. Pour into prepared tin.

9. Bake for 45-50 minutes then leave to cool completely in tin. Tip out onto serving plate, top with berries and dust with icing sugar or cocoa.