For Vanilla Pudding

1/3 cup sugar

2 tablespoons cornstarch

2 cups whole milk

1/2 cup heavy cream

2 tablespoons unsalted butter, cut into pieces

1 whole vanilla beans or 1 tablespoons pure vanilla extract 

For Candied Kumquats

2 cups fresh kumquats

2 cups water

2 cups sugar

Whisk together sugar, cornstarch, and a pinch of salt in a heavy medium saucepan, then whisk in milk, cream and vanilla. Bring to a boil over medium heat, whisking frequently, then boil, whisking, 1 minute. Remove from heat and whisk in butter. Divide among glasses and chill, uncovered, until cold, at least 1 1/2 hours. Thinly slice kumquats crosswise with a sharp knife, discarding seeds. Bring water and 2 cups sugar to a boil in a 2-quart heavy saucepan, stirring until sugar is dissolved, then simmer syrup, uncovered, 8-10 minutes. Stir in kumquats and simmer gently 15-20 minutes. Let stand at room temperature. Spoon over puddings.