Pear Tree Cake

Start with the cocoa sponge cake:
Separate the egg whites from the yolks. Beat the whites with the sugar gradually until you get a meringue.
Add the yolks and beat for another 2 minutes. Sift the flour, unsweetened cocoa powder, and cornstarch, then gently fold them in using a spatula until you have a light, even mixture.
Pour the batter into a greased and floured 20 cm cake pan and bake for about 30 minutes at 180 degrees Celsius (check the doneness by inserting a knife—it should come out clean!).
Unmold and let it cool on a rack. Cover it with plastic wrap and refrigerate.
Prepare the cream:
Soak the gelatin leaves in a large bowl of cold water. In a saucepan, heat the milk with the split vanilla pod (scraping out the seeds).
Whisk the egg yolks, sugar, and add the cornstarch. Remove the pod and gradually pour the boiling milk into the egg mixture while whisking.
Put everything back on medium heat, whisking until you get a thick pastry cream. Off the heat, add the squeezed gelatin, mix, then add the butter and whisk again.
Pour into a shallow dish, cover it with plastic wrap touching the cream's surface. Let it cool in the fridge for about 1 hour until it's completely cold.
Whip the heavy cream and mascarpone in a cold bowl, gradually adding the powdered sugar until you have a firm and light whipped cream.
Whisk the pastry cream to loosen it, then delicately fold it into the whipped cream using a spatula to get the diplomat cream.
Fill a piping bag with the cream and set it aside.
Assembly:
Cut 2 cake circles about 1 cm thick using a cake slicer or bread knife.
Place a pastry ring on a cake board (or plate), place a Rhodoid sheet for easier unmolding, or use parchment paper.
Place the first cocoa sponge cake circle. With a brush, moisten it with pear syrup, and optionally, arrange pear pieces around it.
Add diplomat cream all over and a little on the sponge, spreading it with a spoon, then pour in cubed pear pieces (equivalent to 4 pears).
Add more cream, then the second circle, moisten it with syrup, and finally, add more diplomat cream to cover it all and smoothen with a small spatula.
Refrigerate for at least 8 hours (ideally, overnight).
Decorate with remaining diplomat cream, pear slices, and a sprinkle of unsweetened cocoa powder. Or decorate it as you wish! Enjoy your meal!