Sprinkle the gelatin over 3 tablespoons water in a bowl; let stand 5 minutes.
Melt the chocolate in a heatproof bowl set over a pot of barely simmering water, stirring. Remove the bowl from the pot and slowly whisk in the milk; keep warm.
Whisk the egg yolks, granulated sugar, salt and 1 tablespoon vanilla in a large heatproof bowl. Place the bowl over the pot of hot water and cook, stirring constantly wit a rubber spatula, until smooth and custardlike, 3-5 minutes.
Slowly stir in the warm chocolate mixture and cook until it coats a spoon, 3-5 minuets.
Remove the bowl from the pot and whisk in the gelatin mixture until smooth.
Transfer to a clean bowl, cover and refrigerate until the mixture just begins to set, about 1 hour.
Line the walls of an 8" springform pan with ladyfingers, standing them up (trim the bottoms if desired). Beat the heavy cream in a large bowl with a mixer until it holds soft peaks; sift 1 tablespoon powdered sugar on top, add the remaining 1 teaspoon of vanilla and stir.
Gently fold 1 1/2 cups whipped cream into the chocolate custard until smooth.
Carefully fill the pan with the chocolate cream.
Refrigerate until set, at least 3 hours.
Remove the sides of the pan and transfer the dessert to a platter. Gently toss the raspberries with the liqueur and the remaining 1 tablespoon powdered sugar in a bowl, then arrange the berries on top of the cake.