In a medium saucepan, combine the 4 cups of heavy cream, the slit vanilla bean, and the scraped seeds. Heat over medium heat until steaming but not boiling. Remove from heat and steep for 15 minutes.
In a large mixing bowl, whisk 7 egg yolks, 1 cup sugar, and a pinch of salt until pale and slightly thickened.
Slowly pour warm cream into egg yolk mixture, whisking constantly to temper. Strain mixture through fine mesh strainer into a clean bowl.
Add red food coloring gel to custard mixture, starting with a small amount and adjusting to desired bloody hue.
Preheat oven to 325°F (165°C). Place ramekins in baking dish and fill with custard. Pour hot water halfway up ramekin sides to create a water bath. Bake 40-45 minutes until set but slightly jiggly in center.
Remove ramekins from water bath and cool at room temperature for 30 minutes. Cover and refrigerate at least 4 hours or overnight.
Before serving, sprinkle turbinado sugar on top and caramelize with kitchen torch until golden brown and crispy. Let cool a minute before serving.