Preheat the oven to 350 degrees F.
In a large bowl, beat the egg yolks, sugar, and vanilla, until smooth.
In a medium pot over medium heat, add heavy cream and half and half and cook (stirring occasionally) until bubbles form around the sides of the pan. Remove from heat. Add the chocolate chips and stir until melted and smooth.
Pour a small amount of the hot chocolate cream into the egg yolk mixture and quickly whisk until combined. Repeat until the cream mixture is all mixed in.
Strain this mixture through a sieve into a large bowl with a pouring spot. Discard any chunks in the sieve. Pour the custard mixture between 6 (6-ounce) ramekins.
Place the ramekins in a large baking dish, and fill the dish with hot water to about halfway up the sides of the ramekins.
Bake for 36 - 42 minutes, or until the custard only jiggles slightly when shaken. Remove from the oven and let cool in the water bath for 15 minutes, then move to the refrigerator to cool completely (for at least 4 hours).
After the custard has cooled, sprinkle 1 teaspoon of sugar evenly over the top of each custard. Using a small creme brulee torch, hold the flame about 2 inches above custard surface and rotate it slowly in small circles until sugar is evenly caramelized.