Chill two serving glasses in the freezer for at least 15 minutes.
Slightly warm the caramel sauce until it is pourable, but not hot.
In a blender, combine the vanilla ice cream, whole milk, caramel sauce, optional espresso powder, and a pinch of sea salt. Blend until smooth and creamy.
Taste the milkshake and adjust if needed. Pour the shake into the chilled glasses.
Top with whipped cream and an extra drizzle of caramel sauce. Serve immediately while cold.
Notes
For a thinner shake, add a little more milk. For a thicker consistency, add more ice cream. Chilling the glass helps maintain the cold temperature.