Place milk, cream, sugar and vanilla in a saucepan and bring to a simmer.
Remove from heat and add the white chocolate. Let stand for a few minutes then whisk until smooth.
Place egg yolks in a large bowl. Slowly whisk in hot cream mixture, a little at a time, until fully incorporated. Strain through a fine mesh strainer to remove any lumps.
Place ramekins in a flat baking dish or pan with sides. Fill each ramekin with 6 oz of custard.
Quickly pass the flame of the torch over the custards to pop any bubbles. Place the baking dish a 250℉ oven and fill halfway with hot water.
Bake for 30 minutes, or until it the custards are set when you wiggle them. Carefully remove from the water bath and set aside to cool. Refrigerate until completely cool.
When ready to serve, add a spoonful of sugar to the top and gently tip and tap to coat the top evenly with sugar. Using a clean towel, wipe the rims of the ramekins to make sure they are clean of sugar.
Using a kitchen torch, brulee the tops of the custards until the sugar has caramelized to an even golden brown.