For the meringues:
Sift the powdered sugar and almond flour together.
Make a sugar syrup by heating the granulated sugar and water to 245°F (118°C).
Beat 50 g (about 1/6 cup) of egg whites until foamy, then slowly add the hot sugar syrup while continuing to beat with a stand mixer until the mixture cools. Add another 50 g (about 1/6 cup) of egg whites and beat for another 10 minutes.
Gently fold in the sifted dry ingredients using a spatula. Pipe the mixture onto a baking sheet and bake for 15 minutes at 300°F (150°C). Let cool.

For the whipped ganache:
Grate 1 tonka bean into 3/4 cup (200 ml) heavy cream. Heat the cream, then remove from heat and mix half of it with the baking chocolate (3 1/2 oz / 100 g).
Let cool. Whip the remaining half of the cream until it forms stiff peaks, grate in some more tonka bean, and fold in the chocolate cream while continuing to beat.