Preheat oven to 325 degrees.

Prepare a 10 X 15 " or 13 X 18" baking sheet by lining with parchment paper. See Recipe Note 1 if using a cake mix.

Take your sorbet out of the freeze and allow it to soften on the counter 30-45 minutes while the cake is baking and cooling.

If you are making the cake from scratch - combine the flour and 6 Tbsps sugar in a small bowl and mix thoroughly.

In a separate large bowl, beat egg whites on high. When they are foamy add the cream of tartar and salt and beat until soft peaks form. Add the remaining 6 Tbsps sugar 2 at a time and beat until stiff peaks form. Beat in the lemon juice and vanilla.

Take a fine seive and seive half of the flour/sugar mixture over the egg whites. Fold the flour mixture into the egg whites gently until it is incorporated. Repeat with the remaining flour mixture.

Spread the batter onto your prepared baking sheet. Use an offset spatula to ensure the batter is evenly spread.

Bake at 325 degrees for 20 minutes until cake springs back when lightly touched.

While the cake is baking, prepare your work surface by spreading out a clean tea towel and evenly distributing the icing sugar over the tea towel. Make sure the sugar covers the entire surface that your cake will cover and make sure there are no empty spots. The cake will stick to the tea towel anywhere there is no sugar.

When the cake comes out of the oven, immediately turn it out onto the tea towel. The parchment paper will be on top now. Carefully peel the paper off. Be especially careful around the edges and corners.

Let the cake base cool about 3 minutes. Then, starting at the narrow end gently start to roll the tea towel and cake up together. Set aside on a wire rack to cool completely - about 20 minutes or so.

Prepare your work surface with a large piece of plastic wrap. It should be large enough so the unrolled cake base can rest on it completely.

When cake is cool, gently unroll the cake and tea towel over the plastic wrap surface. As the cake comes free of the tea towel it should be resting on the plastic wrap.

Take your softened frozen filling and spread gently over the cake base. Leave an inch around the side edges and about 3 inches on the narrow edge furthest from you.

Starting at the narrow edge closest to you start to roll the bread base up. The filling will kind of push forward a bit as you roll and will eventually cover the narrow edge at the far end. Use the offset spatula or knife to gently advance the rolling motion if necessary.

Once you have your cake rolled, gently wrap the plastic wrap snugly around the roll and double the ends over. You may need a second piece of plastic wrap to ensure the ends are sealed.

Freeze for at least one hour before serving. Slice about 1 " thick and top each serving with fresh fruit. Will keep frozen indefinitely.