Bourbon-Butterscotch Pudding

INGREDIENTS

• 1/4 (1/2 stick) unsalted butter
• 1 vanilla bean, split lengthwise
• 3/4 (packed) light brown sugar
• 2 1/2 heavy cream
• 1 whole milk
• 1 bourbon or Scotch
• 1/2 kosher salt
• 6 large egg yolks
• 1/4 cornstarch
• 3 sugar
• Crème fraîche and crushed gingersnap cookies (for serving; optional)
• Eight 6-ounce ramekins or bowls