Brazo Gitano

5 eggs, separated

1/4 cup granulated sugar
1/4 cup flour

1/4 cup cocoa powder

1 teaspoon vanilla extract

4 tablespoons sifted confectioners’ sugar

1 cup heavy cream, whipped

1 1/4 teaspoons rum extract

1 tablespoon superfine sugar*

Preheat oven to 350 degrees F. Beat egg yolks and 1/4 cup sugar until thick and smooth. Stir in flour, cocoa and vanilla extract. Blend well. Whip egg whites until stiff, but not dry. Fold into yolk and flour mixture. Butter a 15 x 8-inch baking pan. Line with baking parchment paper or wax paper. Butter well again, and dust lightly with 2 tablespoons of the confectioners' sugar. Pour batter into the pan and spread out evenly. Bake for 15 minutes. Cool for 5 minutes, then turn onto a cloth to cool. After 10 minutes peel paper off. Combine whipped cream, rum and sugar. Adjust to taste. Spread over cake and roll cake like a jellyroll, starting with the long edge. Sprinkle with remaining confectioners' sugar. Serve in slices.
* Superfine Sugar: Put desired amount of granulated sugar in a blender and blend at high speed for about 30 seconds.