6 large egg yolks
1/3 c. granulated sugar
1 tbsp. spiced rum
1/4 tsp. freshly grated nutmeg
1/4 tsp. kosher salt
Pinch ground cloves
1 1/2 c. heavy cream
Whipped cream and ground cinnamon or nutmeg, for serving
Heat oven to 300°F. In a large bowl, whisk together egg yolks, sugar, rum, nutmeg, salt, and cloves. Whisking constantly, gradually add cream and milk to yolk mixture.
Divide mixture among eight 4-oz oven-safe glass canning jars. Place on a rimmed baking sheet, cover with the tops of the jars (but do not screw on), and bake until edges are set but custard is still jiggly in the center, 22 to 24 minutes.
Transfer jars to a wire rack and let cool completely, then refrigerate until chilled, at least 2 1/2 hours and up to 2 days.
To serve, dollop with whipped cream and sprinkle with cinnamon or nutmeg if desired.