Preheat oven to 300 degrees. Have a pot of boiling water ready. Line a baking pan that is 2 to 3 inches deep with a small kitchen cloth. Using a knife, split the vanilla bean lengthwise down the middle and scrape the seeds into a 2-quart saucepan. Add the heavy whipping cream, stir to mix, and set the pan over medium-low heat. Warm the cream until bubbles form around the edges of the pan and steam begins to rise from the surface (this is to merge the cream and vanilla flavors). Remove from the heat and set aside to steep, about 15 minutes. In a large bowl, whisk the egg yolks, salt and 1/4-cup sugar until smooth and blended. Gradually add the cream to the egg mixture, whisking until blended (slowly, you want to temper the yolks, not cook them). Pour the custard through a fine-mesh sieve set over a bowl. Divide the custard among four 5- or 6-ounce ramekins and place the ramekins in the prepared baking pan. Add boiling water to fill the pan halfway up the sides of the ramekins. Bake until the custard is just set around the edges, 45 to 60 minutes. Transfer the ramekins to a wire rack and let cool to room temperature. Cover with plastic wrap and refrigerate for at least 4 hours or up to 3 days. Just before serving, sprinkle 1 tablespoon of the sugar evenly over each custard. Using a kitchen torch, melt the sugar to a caramel. Serve.