Chiffon Cake
Place the egg whites into the bowl of an electric mixer and whip until foamy. Gradually add 1/2 cup of sugar and whip to medium-soft peak.
Combine the remaining cup of sugar with the flour and baking powder and sift together twice. Combine the egg yolks, peanut oil, water and vanilla extract and stir into the dry ingredients one cup at a time.
Fold 1/3 of the whipped egg whites into the batter mixture then fold the result into the remaining whipped egg whites.
Butter and flour two 10" spring form pans and divide the batter evenly between the two. Bake at 300 F. for 15 to 20 minutes then check to see if the cake will pull away from the sides of the pans. Cool and remove from the cake pans.
Lemon Syrup
Combine the sugar and water in a suitable pot and bring to a boil. Cool and add the lemon juice. Reserve.
Passion Fruit Mousse
Place the egg yolks into the bowl of an electric mixer with the sugar and whip until fluffy. Decrease the speed and slowly add the mascarpone cheese (initially drop the bowl position if you have that type of mixer). As the mixture softens, bring the bowl back up and add the passion fruit puree and mix until smooth.
Place the egg whites into the bowl of an electric mixer and whip until foamy. Gradually add 1/4 cup of sugar and whip to very stiff peaks but not dry. Fold the puree and cheese mixture into the whites until combined.
In a small pot, bloom the gelatin in warm water. Drain and add the reserved 4 Tbls. of puree and heat until the gelatin melts. Combine with the above mixture and mix well. Chill and reserve.
Passion Fruit Sauce
Combine the wine, mirin and sugar in a small sauce pan. Heat to a simmer and reduce by half. Add the mango and the passion fruit puree and continue to simmer until the mango is soft. Puree in the blender and add the fresh lime juice.
Assemble And Plate Cake
Slice each chiffon cake into two 1/2" thick layers evenly across the equator. Discard the remainder from the top. Place one layer into the bottom of a clean 10" spring form pan and soak lightly with the lemon syrup. Spoon roughly two cups of the mousse onto the cake and spread around evenly. Repeat in the same with the next two layers. Left over mousse will be used in the next step. Chill overnight in the refrigerator.Melt the white chocolate in a double boiler and stir in the vegetable oil. Mix well and pour enough onto the flat surface of a wax paper lined baking sheets so that the chocolate forms a layer about 1/16" thick. Spread out evenly with an offset spatula. Chill. When the chocolate hardens, cut it into 2" by 4" shingles and peel from the waxed paper. Spread a thin layer of mousse around the sides of the cake and stick the shingles to the mousse, shiny side out.
Fill the cake top with shavings of white chocolate and slice the cake into eight pieces. Place onto serving plates with two ounces of sauce and a few seeds from the fresh passion fruit. Garnish with fresh flower petals.