Making the torta: Preheat oven to 350 degrees F. Grease 8 or 9 inch spring form pan with butter. Cut out a round of parchment paper to fit the bottom of the pan and place inside pan - then set pan aside. Sift together cake flour and baking powder into a bowl and set aside.
In a double boiler over simmering water, whisk together 3 whole eggs, 3 additional egg yolks, 2/3 cup granulated sugar, honey and grated lemon peel. Stir continuously until the mixture is 120 degrees or hot to the touch. Pour the hot mixture into a mixing bowl and beat with mixer on high speed until it triples in volume and resembles a mousse - about 10 minutes.
Gently pour the flour/baking powder mixture over the egg mixture. Using a clean whisk, gently fold the two mixtures together until no lumps remain.
Pour the batter into a pan and bake 30-40 minutes or until an inserted toothpick comes out clean. Set on wire rack and immediately remove sides. Let rest 10-15 minutes then remove the pan bottom and parchment paper. Let completely cool.
Making zabaglione, cream and coffee layers: To make zabaglione, in the top of a double boiler that is not on heat, beat together 4 egg yolks and 1/4 cup sugar for 5 minutes on high speed. Set over barely simmering water. Add Marsala and continue to beat until the mixture triples in volume and holds soft-peaks (approximately 3 to 4 minutes.)
Remove from heat and continue mixing on high speed for 6 minutes, until the mixture has slightly cooled. Set aside zabaglione mixture.
To make mascarpone cream mixture, place the cheese in a bowl and beat at medium speed until smooth. In a large bowl, beat the cream on medium speed until it reaches soft peaks. Add the cheese, confectioner's sugar, 1 egg yolk and vanilla to the cream and continue to beat to stiff peaks stage. Set the mascarpone mixture aside.
To make the coffee mixture, combine espresso, 1 tablespoon granulated sugar, rum and stir well until sugar is dissolved. Set aside.
Slice the torta horizontally into 3 layers with a sharp serrated knife. Place one torta layer into a flat clear bowl or casserole that's slightly larger than the torta's diameter. Brush 1/3 of the coffee mixture over the torta layer. Spread 1/3 of the mascarpone cream evenly over coffee-topped torta. Spread 1/3 of the zabaglione layer over the mascarpone layer - spreading evenly. Repeat with other torta layers, coffee mixture, mascarpone cream and zabaglione mixture. Top with cocoa evenly sifted over the top.
Cover and refrigerate 4-6 hours before serving. Can be held in refrigerator for 3 days. Makes 12 servings.