In a saucepan, combine milk with 1/3 cup of the sugar; heat until scalding.
In a bowl, beat egg yolks with remaining sugar and add a pinch of salt. Slowly whisk hot milk into the egg mixture. Return to saucepan and cook over medium-low heat, whisking constantly, until custard thickens enough to coat the back of a wooden spoon. Do not let mixture boil or it will curdle.
Sprinkle gelatin over water to soften; stir into hot custard and remove from heat. Add vanilla and strain sauce through a fine sieve. Cool custard by setting the pan in a larger container filled with ice cubes. Stir occasionally until sauce starts to thicken and becomes a syrup.
Whip cream until stiff.
Puree raspberries in a food processor or blender and then strain through a sieve to remove seeds.
Fold whipped cream into custard, then fold in pureed strained raspberries.
Pour custard mixture into a chilled 6-cup vessel and cover with plastic wrap. Refrigerate until firm, about 4 hours or overnight.
To serve, dip the bottom of the dish briefly in warm water, dry off and place serving plate over top. Quickly flip it over and turn out onto serving plate. It should slide right out.