Melt the butter in a small pot over medium heat and add the sugar. Whisk until the sugar is mostly dissolved. Slowly add in the heavy cream, spices, and sea salt and whisk constantly until the mixture comes to a gentle boil. Reduce heat to low and simmer for 2-3 minutes, whisking frequently, until the mixture thickens.
Remove the caramel from the heat and whisk in the vanilla bean paste. Use immediately or transfer to an airtight container for later use. The caramel will thicken as it cools. If using later, reheat the caramel in a microwave on low in 10-second increments until pourable and warm.
For the Macchiatos:
Pour the espresso into two glasses and then stir in the caramel sauce. Start with 1-2 tablespoons per glass and then add more, as needed, to meet your tastes. Pour the frothed milk over top and garnish each glass with a dollop of whipped cream, another drizzle of caramel, and a dusting of chai spice. Serve immediately.