In a medium saucepan over medium heat, melt the sugar while constantly stirring until it turns golden brown and begins to bubble. Slowly add the cream, whisking continuously to avoid lumps. Let it simmer for 2-3 minutes until thickened, then remove from heat and stir in the vanilla extract. Let it cool to room temperature.

In a medium saucepan, combine the heavy cream and milk. Heat the mixture over medium heat until it's warm, but not boiling. In a separate bowl, whisk the egg yolks and sugar until pale and slightly thickened. Gradually pour the warm cream mixture into the egg yolks while whisking to temper the eggs. Return the mixture to the saucepan and cook over low heat, stirring constantly, until it thickens enough to coat the back of a spoon (about 5-8 minutes).

Remove from heat and strain the custard through a fine mesh sieve into a clean bowl to remove any cooked egg bits. Let it cool slightly, then mix in the cooled caramel sauce and vanilla extract. Cover the bowl with plastic wrap, pressing it directly onto the surface of the custard to prevent a skin from forming, and refrigerate for at least 4 hours or overnight.

Once the base is fully chilled, pour it into your ice cream maker and churn according to the manufacturer's instructions, usually for about 20-30 minutes. In the last 5 minutes of churning, add the toffee bits and chopped roasted nuts.

Transfer the ice cream to an airtight container, smoothing the top with a spatula. Cover and freeze for at least 4 hours or until firm.

Serve:

Let the ice cream sit at room temperature for a few minutes before scooping. Serve in bowls or cones, topped with extra toffee, caramel drizzle, or chopped nuts, if desired.