Preheat oven to 275 degrees. Whisk the cream, egg yolks, sugar, and vanilla extract together in a bowl. Mix it all up until it gets nice and creamy. Pour this mixture into ramekins. (It will evenly distribute between four 7-ounce dishes.)
Place the ramekins in a baking pan. Fill the baking pan with hot water, about halfway up the sides of the ramekins. Place the pan with the ramekins in the oven for 45 minutes to an hour or so. After 45 minutes, check them every ten minutes. You'll know they're done when you can stick a knife in one and it comes out clean. Remove the ramekins from the baking pan, set them on the counter, and let them cool for 15 minutes or so.
Then, put them in the refrigerator and let them chill overnight.
Sprinkle a thin layer of the light brown sugar on the top of each. Make sure it's a THIN layer, but also make sure it completely covers the custard.
Preheat your toaster oven to “Broil” and place ramekins in broiling tray filled with water (add as much water as possible to keep ramekins cool), let brown sugar caramelize (about 2min), then place ramekins in a fresh water filled baking tray to cool for a minute.