Slice the vanilla pod lengthwise, scrape out the seeds, and put the seeds and bean in a saucepan with the cream.
Bring to a simmer. DO NOT BOIL. Remove from heat and remove the vanilla pod.
Whisk together about 1/4 cup of the cream with the matcha powder to remove all the clumps. Then, whisk the matcha mixture into the rest of the cream to combine.*
Heat the oven to 320F.
Beat the egg yolks and sugar until light and fluffy in a bowl you can use in a bain-marie (glass bowl that fits over a sauce pan filled with simmering water). Stir in the warmed cream. Make sure to mix well.
Over the bain-marie heat the cream mixture stirring constantly until it coats the back of a spoon, ~8 minutes.
Strain the mixture to make sure it is smooth.
Divide the mixture between 4 ramekins.
Place the ramekins in a deep roasting tin. Fill the tin half-full with boiling water. Place it in the oven and cook 20 minutes.
Remove from the oven. Remove from the water to stop them from continuing to cook. Let cool to room temperature, then transfer to the refrigerator and cool overnight.
When ready to serve, take them out of the refrigerator 20 minutes before serving so they come to room temperature.
BRULEE: If you have a brûlée torch, add a covered layer of fine caster sugar and shake off the excess into the next ramekin. Gently move the flame around to evenly melt the sugar. If you do not have a torch, heat the broiler to high. Add a covered layer of icing sugar and shake off the excess into the next ramekin. Then, place under the grill. WATCH CAREFULLY! Let cool before serving.
Notes
* This can also be done in a blender if you have one, but isn't necessary if you are first whisking together the 1/4 cup of cream and matcha powder to remove the clumps.Before serving allow the crème to come to room temperature before you brûlée the tops. This helps the sugar melt evenly as you torch the tops. Caster sugar is the sugar of choice for crème brûlée because it is fine and will melt more evenly than coarse sugar. If you do not have caster sugar, you can run granulated sugar in a food processor to break it down.