Scoop the ice cream in a microwave-safe bowl. Microwave the ice cream for 30 to 40 seconds or until completely melted. Allow to cool for 5 minutes.
Add the egg yolk into the melted ice cream and whisk well.
Pour the mixture into a ramekin. Place the ramekin in a pan. Pour hot water into the pan to come roughly halfway up the sides of the ramekin.
Bake for 40-50 minutes. The crème brûlée should be set, but still a little jiggly in the middle. Remove the ramekins from the roasting pan, allow to cool to room temperature, cover with plastic wrap and refrigerate for at least 2 hours, and up to 3 days.
Remove the crème brûlée from the refrigerator for at least 30 minutes before browning the sugar on top.
Sprinkle a tablespoon of sugar on top of each crème brûlée. Using a torch, melt the sugar to for a crispy top. If you don’t have a torch, you can broil the crème brûlée to melt the sugar. Keep an eye on it, to make sure you don’t over cook it. Allow the crème brûlée to sit for at least 5 minutes before serving.
You can also make various flavor by using different ice cream flavors. If you are using flavored ice cream, use 1 egg instead of 1 yolk.