In a food processor, break down marzipan, the egg white and apple sauce and turn into paste; rather firm than too soft. Use the #825 star pastry tip and pipe out 8 cookies onto a baking tray lined with a silicone baking mat. Let dry out overnight on the counter.
In a food processor, blend almond meal, flour and powdered sugar. In the stand mixer, beat egg whites with cream of tartar and 1/3 of the sugar to stiff peaks; adding remaining sugar as it goes. Fold the dry ingredients into the meringue and fill up each almond cookie cavity. Pipe out leftover capucine biscuit batter onto disks onto another baking tray.
Mix a couple of pinches of agar-agar in 1/2 cup/125g hot water. Set aside and use at room temp.
Bake cookies at 375ºF/190ºC for about 18 min. For a glossy finish, brush out the sides of almond cookies with the lukewarm agar-agar glaze. Let cool.
In a food processor, blend warm pistachios with oil and almond extract until it turns to paste. The recipe can be multiplied. Pistachio paste can be stored for weeks.
Pistachio Paste: In a food processor turn into paste: pistachio (preferably skinned) ≈ 5 ounces (150g) with a few drops of almond extract. Keep refrigerated for months.
Soak gelatin in cold water to soften; and drain. Bring to a boil milk with a third of the sugar, vanilla paste and pistachio paste. Meanwhile, combine egg yolks with remaining sugar and corn starch. Temper yolk mixture with hot milk, transfer mixture into the saucepan, whisk well and bring custard to boil, and cook for 2 min whisking constantly. Remove from the heat, mix in gelatin and mascarpone. Transfer custard onto a frozen baking tray lined with plastic wrap. Cover with plastic wrap in contact and chill overnight. Using a stand mixer fitted with the whisk attachment, whip heavy cream to medium-firm peaks and transfer to a bowl. In the same mixing bowl, smooth out pistachio custard and fold in whipped cream.
Pipe out dollops of diplomat pistachio cream onto each cookie leaving sides uncovered. Arrange raspberry halves or strawberries. Sprinkle some crushed pistachio and decorate with edible gold leaf if desired. Enjoy!