Combine the egg yolks, whipping cream, and 1/4 cup of the sugar in a bowl. Whisk to combine.
Using a dull knife, scrape the seeds out of the vanilla bean and add it to the cream mixture. (You should have about 1/8 teaspoon of vanilla bean seeds).
Whisk the mixture together very well. Pour into two 4-ounce ramekins.
Meanwhile, take two 12-inch-long pieces of foil and roll them up into “snake” shapes. Then curl each one into a circle and pinch the ends together. Place them side by side in the bottom of your slow cooker.
Place each ramekin on top of each foil ring.
Carefully pour boiling water into the slow cooker (don’t splash water on the custards!) until the water reaches about one-third of the way up the side of the ramekins.
Turn the slow cooker to LOW and cook for 2 to 2 1/2 hours. When done, the custards should be set – poke one with a knife to be sure.
Cover and chill the custards at least 6 hours.
Before serving, sprinkle the remaining 2 teaspoons of sugar evenly over both custards and torch with a culinary torch until brown.