- In a large bowl, whisk together the eggs, oil and milk.
- Fold in the cinnamon, flour, and bi-carb soda until just combined.
- Add pineapple, carrots, and walnuts. Pour the mixture into a 22cm greased ring pan that is microwave-safe and heat-proof.
- Place the cake pan on a microwave rack or a cup and plate upside down.
- Choose 50% power and select 12 minutes of cooking time. Press the START button
- Check that the cake is done with a skewer after 10 minutes. Remove the cake from the pan and let it cool on a rack. Place absorbent paper over the cake if it has spots of moisture on its surface.
- Beat butter, cream cheese, and vanilla with an electric mixer on medium speed for 1-2 minutes or until well blended.
- Once sugar is added, increase the speed to mix well.
- Spread over cooled cake, and garnish with extra walnuts.