Preheat the oven to 325°F (165°C). Grease 6 (4-ounce) ramekins and set aside.

Combine cream and milk in a large pot. Cut vanilla bean lengthwise and scrape vanilla bean seeds into the saucepan; add vanilla beans and salt. Bring to a low boil.

Whisk together rice, eggs, egg yolks, ½ cup sugar, and cinnamon in a large bowl until well combined.

Remove vanilla beans from the cream mixture. Slowly pour hot cream mixture in a thin stream into egg-rice mixture, whisking constantly to prevent eggs from cooking. Pour mixture into the prepared ramekins.

Place the ramekins on a large baking sheet and put in the oven; carefully pour enough hot water to reach halfway up the sides of the ramekins.

Bake until edges are set and centers are still jiggly, about 25 minutes. Remove ramekins from the water bath and place them on a wire rack to cool for at least 10 minutes. Cover and chill in the refrigerator for at least 3 hours.

When ready to serve, turn the oven broiler to high. Remove ramekins from the refrigerator and sprinkle the remaining ¼ cup sugar evenly over the tops.