Cake
6 room temperature separated eggs
1 1/4 cups sugar
1/4 cup hot water
1 teaspoon vanilla extract
3/4 cup sifted cake flour
1/2 cup sifted cocoa
3/4 teaspoon cream of tartar
1/4 cup melted, cooled butter
Sugar Syrup
1/3 cup sugar
1/3 cup water
1 tablespoon dark rum or orange juice
Filling
1 1/2 cups heavy whipping cream
3 ounces chopped semi-sweet chocolate
2 tablespoons dark rum or orange juice
3 ounces white chocolate
4 tablespoons water
3 ounces chopped milk chocolate
Glaze
3 ounces chopped semi-sweet chocolate
1/4 cup butter
1 1/2 teaspoons corn syrup

Cake
Heat oven to 350°F. Grease 9 inch springform pan and sprinkle with flour. Line pan with parchment paper. Combine egg yolks and 1/2 cup sugar. Mix well. Set bowl over saucepan of barely simmering water. Bowl should not touch water. Whisk egg mixture constantly 40-60 seconds till sugar is dissolved and mixture is warm to touch. Beat on medium-high speed for 5 minutes till mixture is thick and ribbon forms. Reduce speed to medium. Add water and vanilla, beating till combined. Gradually sift and fold flour and cocoa into yolk mixture. Fold till thoroughly combined. In another large bowl, beat egg whites till frothy. Add cream of tartar. Beat on medium-high speed till soft peaks form. Gradually add remaining sugar, beating till stiff peaks form. Fold 1/4 of egg white mixture into batter to lighten mixture. Gently and quickly fold in remaining egg whites till combined. Place butter in medium bowl. Add large spoonful of batter to butter; whisk till well mixed. Fold mixture back into batter. Pour batter into prepared pan, spreading evenly. Bake 35-40 minutes till cake springs back when lightly touched and begins to shrink from sides of pan. Cool in pan on rack 20 minutes. Run knife around pan edge to loosen cake. Remove sides of pan. Turn cake out onto rack and remove base and paper. Cake may sink slightly during cooling. If it does, press edges down to even cake. When cool, slice cake horizontally into 4 layers.
Sugar Syrup
Combine sugar and water in small saucepan. Bring to boil, stirring till sugar dissolves. Stir in rum and cool.
Filling
Beat cream on medium-high speed till soft peaks form. Refrigerate while preparing chocolates. Melt semi-sweet chocolate and rum together; stir till smooth. Cool to room temperature. Melt white chocolate and 2 tablespoons water together; stir till smooth. Cool to room temperature. Melt milk chocolate, coffee powder and remaining water together; stir till smooth. Cool to room temperature. Add 1/3 of whipped cream to each bowl of melted chocolate. Fold till well mixed.
Assembly
Place bottom layer of cake in 9 inch springform pan. Brush generously with sugar syrup. Spread semi-sweet chocolate mixture on cake layer. Place second cake layer over semi-sweet chocolate mixture. Brush with sugar syrup. Spread with white chocolate mixture. Top with third cake layer. Brush with sugar syrup. Spread with milk chocolate mixture. Top with final cake layer. Brush with sugar syrup. Gently press to even cake layers. Cover and refrigerate 2-4 hours.
Glaze
Combine all ingredients. Melt and stir till smooth. Let stand till thickened but still pourable. Pour glaze onto center of chilled cake. Spread over top. Use as few strokes as possible to spread. The more strokes used, the duller the glaze will be. Refrigerate till ready to serve. Before serving, remove sides of pan and smooth sides of cake if necessary.