Pre-heat the oven to 350°. Grease a 9 inch (24 cm) springform cake pan.
ITALIAN SPONGE CAKE
Start by making the sponge cake. Beat on medium-low speed the eggs and sugar until well mixed (2 minutes) add flour and baking powder and continue to beat on medium speed for 2-3 minutes or until smooth. Pour into prepared cake pan and bake for approximately 30 minutes or until tested done. Let cool completely. Once the cake is cool slice off the top and bottom of the cake leaving the centre layer (approximately 1/2 inch / 1 1/4 cm thick).
While the cake is baking make the Pastry Cream Filling. In a medium pot, add the milk, cream and orange peel and heat to very hot over medium heat, do not boil. Remove from heat and let cool to warm. Remove the peel and discard. In a medium pot add yolks and sugar, whisk together until combined, then add the vanilla and flour and combine. Place the pot over medium / low heat, add warm milk/cream, whisking continuously until almost thickened then add the orange juice and continue until thick. Remove to a glass bowl, cover with plastic wrap (make sure wrap touches the cream mixture) and refrigerate at least 1.5 hours.
While the cake is cooling and the Pastry Cream is chilling. Prepare the puff pastry. Roll out the pastry and gently roll a couple of times with a rolling-pin. Cut the puff pastry a little larger than the 9 inch cake pan. Place on a parchment paper lined cookie sheet, prick the dough with a fork (see photo). Sprinkle with powdered / icing sugar and bake for approximately 15-20 minutes or until golden. Let cool completely.
In a medium pot on medium heat, add the water, sugar and juice, heat until boiling then reduce heat and simmer for 5-7 minutes. Remove to a small bowl and let cool completely.
In a large bowl add the cream and beat until soft peaks appear than add the sifted powdered / icing sugar and beat until stiff. Fold into the chilled Pastry Cream.
PUTTING THE CAKE TOGETHER
On a flat plate place one teaspoon of pastry cream then place 1 puff pastry round on top (this keeps the cake from slipping), top with 1/4 of the cream filling, place the sponge cake layer on top and top with almost all of the orange syrup, then top with 1/4 of the cream filling, place the remaining puff pastry layer on top (at this point I found it best to refrigerate the cake for 30 minutes). Then finish frosting the cake and sides with the remaining cream filling. Sprinkle with ground almonds. Refrigerate cake for at least one hour before serving. Enjoy!
If you decide to use a rum syrup instead of an orange syrup. In a medium pot on medium heat, add the water, and sugar, heat until boiling then reduce heat and simmer for 5-7 minutes. Remove to a small bowl and let cool completely then add 2 tablespoons of rum.