How to Make It
In a large saucepan, combine the wheat berries, 4 quarts water, and 1 teaspoon salt and bring to a boil. Cook until tender but still slightly chewy, about 1 hour; drain.
Meanwhile, in a medium saucepan, whisk together the sugar, cornstarch, and 1/4 teaspoon salt. Gradually whisk in 1/4 cup of the milk until a smooth paste forms. Whisk in the egg yolks, cream, and the remaining 3 1/4 cups milk.
Cook the mixture over medium heat, stirring constantly, until the first small bubbles start to sputter and the pudding has thickened, 6 to 8 minutes (do not allow it to boil). Remove from heat and stir in the raisins, butter, vanilla, and wheat berries.
Divide the pudding among six 8-ounce ramekins (or transfer it to an 8-inch square baking dish). Sprinkle with the cinnamon. Serve warm or chilled.