Preheat oven to 325°F (170°C). Divide hot Vanilla Bean Caramel among 4 (4-ounce) ramekins. Refrigerate until hardened, about 15 minutes. In a medium saucepan, bring milk, cream, sugar, and salt to a simmer over medium heat. Remove from heat. In a medium bowl, whisk together eggs, egg yolk, and vanilla bean paste. Slowly add hot milk mixture to egg mixture, whisking constantly. Return mixture to pan, and cook over medium heat, stirring constantly, until mixture is thickened, about 2 minutes. Strain mixture through a fine-mesh sieve into a heatproof measuring cup. Place ramekins in a 9-inch square baking dish. Pour cream mixture over Vanilla Bean Caramel, filling almost to top of ramekins. Carefully place baking dish in oven. Pour enough hot water into dish to come about one-third of the way up sides of ramekins, being careful not to splash any water in ramekins. Bake until edges are just set but centers are still jiggly, about 30 minutes, rotating dish halfway through baking (being careful not to splash water). Using a towel, carefully transfer hot ramekins to a wire rack, and let cool completely. Cover and refrigerate for 4 hours. Run a sharp knife around edges of ramekins to loosen. Invert onto serving dishes, tap top of ramekins, and remove. Serve immediately.
Vanilla Bean Caramel
In a medium stainless steel saucepan, cook sugar and vanilla syrup over medium heat until medium amber colored, 5 to 7 minutes. Use immediately.