Sprinkle the gelatin over 3 tablespoons water in a bowl and let stand, 5 minutes. Melt the chocolate in a heatproof bowl set over a pot of barely simmering water (do not let the bowl touch the water), stirring occasionally. 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 with a rubber spatula, until smooth and slightly custardlike, 3 to 5 minutes. Slowly stir in the warm chocolate mixture and cook until it coats a spoon, 3 to 5 minutes. Remove the bowl from the pot and whisk in the gelatin mixture until smooth. Transfer to a clean bowl, cover and refrigerate until the custard just begins to set, about 1 hour.
Line the walls of an 8-inch 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 confectioners' sugar on top, add the remaining 1 teaspoon 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 confectioners' sugar in a bowl, then arrange on top of the cake.