Place two serving glasses in the freezer to chill while you prepare the frappe — this keeps the drink colder longer.
Add the chilled strong coffee, caramel creamer, milk, and vanilla extract to a blender. Briefly pulse on low for about 5–8 seconds to combine the liquids and emulsify.
With the blender running on medium, add the ice in two additions: start with half the ice and blend until roughly broken up, then add the remaining ice and pulse until the mixture is thick and slushy. Stop and scrape the sides once if needed to keep texture even.
Check the consistency — if it’s too thin, add a few extra ice cubes and pulse; if it’s too icy, blend a few more seconds. Aim for a creamy, spoonable frappe texture.
Remove the chilled glasses from the freezer. Swirl a tablespoon of caramel sauce inside each glass for a decorative stripe and extra flavor.
Pour the blended caramel frappe evenly into the prepared glasses. Let drinks rest 20–30 seconds so the foam settles for a smoother top.
Top each glass with a generous swirl of whipped cream and finish with a drizzle of caramel sauce. Serve immediately with a straw.