Instructions

Blackberry jelly roll

1. Preheat oven to 350°F.
2. Oil a half sheet jelly roll pan (12" x 16" x 1" -- large cookie sheet size). Cut a sheet of parchment paper to fit in bottom of the pan. Place the parchment sheet on top of the oiled bottom and then oil the parchment sheet. Set aside.
3. Oil the bottom of a 9 inch round cake pan. Line with parchment paper and oil the top of the parchment paper.
4. Beat egg yolks and ⅔ cup sugar until light and thick (about 3 minutes).
5. Add in vanilla, salt and flour.
6. In a separate bowl, beat egg whites until frothy. Add cream of tartar. Continue beating until soft peaks form. Gradually add remaining ⅓ cup sugar and beat until stiff but not dry peaks form.
7. Fold egg white meringue into egg yolk mixture one third at a time. Be careful not to deflate the egg whites.
8. Scoop out 1 ½ cups of the batter and spread in the round pan.
9. Pour the remaining batter into prepared jelly roll pan and spread evenly.
10. Bake for 15-20 minutes or until golden brown. Top should spring back when lightly touched.
11. While the cake is baking. heat the jam in a microwave until it melts. Put it through a sieve to remove the seeds.
12. When the cake has cooled to warm (not hot), loosen the edges with a sharp knife. Dust the top lightly with powdered sugar and place a piece of parchment paper on top. Invert the pan with the parchment paper on top onto a cooling rack.
13. While the cake is still warm put the rectangular jelly roll sponge cake on a parchment dusted with powdered sugar.
14. Spread a thin layer of blackberry jam on top of the rectangular cake and roll one long side towards the other in a tight spiral so you have a 16" long jelly roll.
15. Wrap in parchment and refrigerate the jelly roll until you are ready to use it. Wrap the round sponge until you are ready to use it.

Blackberry Mousse

1. In a small bowl, sprinkle gelatin over 3 tablespoons water. Let stand until softened (about 5 minutes).
2. Puree the blackberries and remaining 3 tablespoons water in a food processor.
3. Put through a sieve into a small saucepan. There should be about 1 ½ cups juice. Add sugar and bring to a boil. Reduce heat and simmer about 5 minutes.
4. Stir in softened gelatin.
5. Let cool to room temperature.
6. In a medium bowl, beat the egg whites until firm peaks form.
7. Fold into berry mixture until no white streaks remain.
8. In a large bowl beat the heavy cream until stiff peaks form. Do not overbeat or you will have butter.
9. Fold the whipped cream into the berry mixture.

Assembly

1. Find a bowl with a 10 inch wide opening at the top. If you don't have a bowl that size, you can use a larger bowl and not fill it all the way to the top.
2. Line the bowl with plastic wrap leaving enough over the edges that you can fold it back over the charlotte when the bowl is filled.
3. Cut your blackberry jelly roll into ½" slices. Line the bowl with slices. Work from the bottom of the bowl towards the top. Gently fit the slices together to minimize gaps.
4. Pour the blackberry mousse into the jelly roll lined bowl. Place the round sponge cake on top and fold the plastic wrap over the top to seal everything.
5. Refrigerate at least 6 hours (overnight is best).
6. Unfold the plastic wrap from the top of the bowl and place the serving dish on top of the bowl. Invert and gently tug on the plastic wrap to remove the charlotte from the bowl.
7. Just before serving, remove the plastic wrap from the charlotte.