Whisk matcha powder into sugar, then whisk into cream mixture.
Heat cream mixture over medium. Whisk frequently to dissolve the sugar. Turn off the heat when the cream just starts to steam and small bubbles start to form around the edges (about 5 minutes). Let cool for 2 minutes.
Meanwhile, put egg yolks into a large measuring cup with a spout and whisk until combined.
Slowly add a few ounces of the hot matcha cream into the eggs, whisking constantly. Then slowly pour in the rest of the cream while continuing to stir constantly.
Whisk in salt and vanilla.
Use a large spoon to scrape off most of the foam on top that was generated by brisk whisking.
Bring a kettle to boil with hot water.
Fill 6 4-ounce ramekins with matcha custard, and put ramekins in a 9x13 baking dish.
Put baking dish in oven. Pour in very hot water around the ramekins, about ¾ of the way up the sides.
Bake for 30-35 minutes, or until custards are set, but still jiggle slightly in the middle.
Remove ramekins from oven and let cool slightly. Then refrigerate for at least 3 hours and up to 3 days.
When ready to serve, sprinkle 2 teaspoons sugar over the top of each custard’s surface, covering completely.
Hold a kitchen blowtorch a couple of inches from the surface of the custard, and turn on. Caramelize the sugar by moving the blowtorch in circles over the custard until the sugar melts and browns.
Repeat for remaining custards.
Serve immediately, or chill in the refrigerator for 30-60 minutes.
Notes
Expert Tips: Fill ramekins to the top with the matcha custard mixture because custard will settle as it bakes and drop slightly.Wondering if the water bath is really necessary? Yes, it is! The water bath makes sure the custards cook slowly and gently so they don’t overheat and break. Don’t overcook your custards. You want them to wobble or jiggle when you shake the side a bit. If the center is sloshing around, they are not done. On the other hand, don’t wait until they are fully set before pulling out of the oven—they will continue to firm up as they cool.If you want to be extra sure, use a high-quality instant read thermometer to test the center temperature. The custard is done when it reaches between 170 and 180 degrees. Don’t have a kitchen torch? You can put the custards under the broiler instead. Make sure the ramekins are about 3-4 inches from the heating coil, and watch carefully so they don’t burn. Broilers can be higher risk since they can take longer to caramelize, and in the meantime warm the custard up so much that it curdles.Make-Ahead Tips: If you do decide to chill your crème brûlées after caramelizing, don’t chill longer than 3 hours or the sugar topping will soften.You can refrigerate baked custards for up to 3 days before adding the sugar crust.Freezing is not recommended.