Scrape the vanilla bean seeds into a saucepan. Stir in the pod, 3 cups cream, the sugar, milk and 1/4 teaspoon salt. Bring to a boil, stirring, until the sugar dissolves.
In a bowl, beat the 3 eggs. Whisk in the cream mixture; pour into the saucepan. Cook over low heat, stirring, until a candy thermometer registers 170 degrees . Strain into a bowl to cool. Press wax paper onto the surface and refrigerate for 3 hours. Transfer to an ice cream maker and process according to manufacturers instructions; freeze for 4 hours.
Preheat the oven to 350 degrees . In a bowl, combine the oats and coconut; place the pecans in another bowl. Whisk together the egg white and 1/2 teaspoon salt, then divide between the oat mixture and the pecans, stirring to coat. Without combining, transfer the mixtures to a parchment-lined baking sheet. Bake until the coconut is golden, stirring halfway through, about 15 minutes; let cool.
In a saucepan, bring the chocolate, the remaining 1/3 cup cream, the corn syrup, brown sugar, cocoa and remaining 1/4 teaspoon salt to a boil. Simmer, stirring, until thickened, 2 minutes; stir in the vanilla extract.
Place 2 scoops of ice cream in each of 6 parfait glasses; layer with the pecans, coconut oats, more ice cream and the fudge sauce.