Line a 15 x 10-inch jelly roll pan with parchment paper. Preheat oven to 350°F (180 °C)
Separate the 6 eggs, placing the egg whites in the bowl of your stand mixer and the egg yolks in a separate bowl.
Whisk together egg yolks and vanilla extract.
In a separate bowl, whisk together the cocoa and ⅓ cup of sugar. Set aside.
Whisk the egg whites until soft peaks form.
Gradually add the ⅓ cup of sugar and continue to beat until stiff peaks form. Set aside.
Add the cocoa-sugar mixture to the egg yolks. Whisk together until smooth.
Fold about a cup of the whipped egg whites into the chocolate batter until the batter becomes lighter in texture.
Slowly incorporate the rest of the egg whites by folding gently.
Spread batter evenly in the prepared jelly roll pan and bake for approximately 20 minutes or until the cake springs back when lightly pressed.
Once the cake is removed from the oven and has cooled down in the sheet pan for about 5 minutes, loosen the sides and invert on a clean tea towel sprinkled with icing sugar.
Remove the parchment paper by gently pulling it back. Allow to cool to room temperature.
The Rum Syrup:
Combine the sugar and water in a small saucepan.
Over medium heat, bring to a boil and stir to dissolve sugar (boil for about 1 minute).
Remove from heat and add the rum.
Cool to room temperature.
The Ricotta Filling:
Whisk all the ingredients for the filling (except for the chocolate chips) until smooth and creamy. Fold in the chocolate chips. Set aside.
The Chocolate Ganache Frosting:
Place chocolate in a heatproof bowl and set aside.
In a small saucepan,over medium heat, heat butter and cream together.
Bring to just under a boil. Remove from heat.
Pour the hot cream mixture over the chocolate and let it sit for a minute to soften it.
Gently whisk the mixture until smooth and glossy. Then, just let it cool to room temperature, stirring occasionally to get the right consistency.
The Assembly:
Once the cake is at room temperature, cut into thirds.
Place one of the thirds on your serving platter, and brush the top with the rum syrup over the entire surface.
Spread ½ of the ricotta cheese filling on this bottom layer.
Place the second cake layer on top and brush it with the rum syrup. Spread the rest of the ricotta filling.
Finally, place the third cake layer over the ricotta filling and brush with the rum syrup.
Whisk the chocolate ganache one final time and spread over the entire surface and sides.
Garnish with chocolate shavings (optional).
Chill the cake for at least an hour before serving to allow the flavors to meld together. It can be made 24 hours in advance.
Video
Notes
Drain the ricotta. You risk getting a wet mixture that will "leak" if the ricotta has too much moisture.
Allow the cake to come to room temperature after it is baked. Since both the ricotta cheese filling and the chocolate ganache are heat sensitive, do not start assembling until the cake is at room temperature.
Rum syrup: Cool to room temperature before brushing on the individual layers.
Troubleshooting the ganache: If the chocolate ganache is not firming up as desired, try placing it in the refrigerator for about 3 minutes. This brief chilling period can help it set and reach the desired consistency.
Please keep in mind that the nutritional information provided below is just a rough estimate and variations can occur depending on the specific ingredients used. *adapted from Homemaker's Magazine