Place the marshmallows on a parchment-lined sheet pan. Move the oven rack as high as it will go and place pan on rack. Broil marshmallows for 2-3 minutes, rotating after 1 minute so that all sides get toasted. (Note: Watch the marshmallows carefully while they are broiling so that they don’t burn! If you have a kitchen torch, that’s another great way to toast the marshmallows quickly.) Set toasted marshmallows aside.

Using a medium saucepan, heat the milk until it just begins to simmer.

Meanwhile, whisk together the sugar, salt and egg yolks in a medium bowl. Gradually pour half of the hot milk into the egg yolk mixture, whisking vigorously the entire time.

Transfer the egg yolk mixture into the saucepan with the remaining milk. Cook over medium-low heat, stirring constantly, until the mixture thickens and coats the back of a wooden spoon (6-7 minutes).

Remove mixture from the heat and stir in the heavy cream and vanilla extract. Pour the mixture through a fine-mesh strainer into a clean container. Allow cream mixture to cool for about 10 minutes.

Pour the cream mixture into a blender and add about 20 of the toasted marshmallows; blend until smooth (about 1-2 minutes).

Coarsely chop the remaining 5 toasted marshmallows. Transfer the cream mixture into a bowl, and stir in the chopped marshmallows. Cover bowl with plastic wrap, pressing the plastic directly to the surface of the mixture. Refrigerate overnight.

Pour the ice cream mixture into an ice cream maker and freeze according to the manufacturer’s directions. (If you prefer a harder ice cream, just freeze the ice cream for several hours before serving.)

(optional) Garnish with graham cracker crumbs and a drizzle of chocolate syrup.