For the Ice Cream:

1. Preheat the oven to 400°F and line a baking sheet with parchment paper. Spray lightly with cooking spray. Place the banana halves on the baking sheet, cut side up, and sprinkle evenly with 2 tablespoons of brown sugar. Bake for 10-15 minutes or until soft and beginning to caramelize. Cool completely, chop into bite-size pieces, and set aside.
2. Halve the vanilla bean lengthwise and scrape the seeds into a saucepot. Add the vanilla bean pod, cream, milk, sugar, and salt and whisk to combine. Bring the mixture to a simmer, stirring occasionally to dissolve the sugar. Remove from heat and discard the vanilla pod.
3. Beat the egg yolks in a large mixing bowl. Slowly stream in the hot cream mixture, whisking constantly. Return the mixture to the pot and place over low heat.
4. Cook the custard, stirring constantly, until thickened (it should coat the back of a spoon).
5. Remove from heat and strain the custard through a fine-mesh sieve into a clean bowl. Whisk in the rum and half of the roasted banana pieces and cover the mixture with plastic wrap. Chill for a couple hours in the fridge. Stir the mixture well to make sure the bananas are still mixed throughout and then process according to your ice cream maker’s instructions. Gently stir in the remaining half of the bananas and then spoon the mixture into an airtight container. Freeze until firm. Soften for a few minutes before scooping.

For the Chocolate Sauce:

1. Heat the cream and butter in a small saucepan and once warm, stir in the chocolate. Stir constantly until the chocolate is melted and the sauce is glossy. Sprinkle in the sea salt and taste for saltiness. Adjust as needed. Keep warm until ready to serve the milkshakes.

For the Bruléed Bananas:

1. Just before you are ready to serve the milkshakes, place the slices of banana on a heat-safe surface, like a foil-lined baking sheet. Sprinkle the brown sugar over the slices evenly and then, using a kitchen torch, melt the sugar over the banana until caramelized and golden. Alternatively, you could place the baking sheet under the broiler for a few minutes, but make sure you watch it the entire time because it can burn very quickly.

For the Milkshakes:

1. Place the ice cream, milk, and rum (if using) in a blender and blend until mostly smooth. Pour into glasses and garnish with the salted chocolate sauce, whipped cream, warm bruléed bananas, and chopped nuts. Serve immediately.