In a medium saucepan, combine the cream, milk and sugar. Use a sharp knife to scrape the vanilla beans from the pod and add to the saucepan. Place over medium heat and stir to dissolve the sugar. Heat just until bubbles appear at the edges and mixture is steaming (do not bring to a boil).
Meanwhile, whisk together the egg yolks and cornstarch in a medium bowl. Add the hot cream mixture in a slow steady stream while whisking constantly.
Pour mixture back into the saucepan and return to medium heat. Cook, stirring constantly with a spatula to scrape the bottom, until mixture is thickened. This will take 3-5 minutes. Once thickened, cook for an additional 1 minute, while continuing to stir.
Remove from heat and pass custard through a mesh strainer to remove any lumps. Spoon into individual ramekins. Place in the fridge, uncovered, to set up for at least 2 hours.
When ready to serve, sprinkle ramekins generously with granulated sugar. Working with one at a time, pass a kitchen torch over the surface until sugar melts and caramelizes. Serve immediately.
You may substitute 1 tablespoon vanilla extract for the vanilla bean. After the custard has thickened, remove from the heat and stir in the vanilla before passing through a mesh strainer.
Can be made up to 24 hours in advance. Brûlée topping just before serving.