For the Chocolate Filling
For the Marshmallow Topping
For the Marshmallow Frosting
For the Crust
Preheat oven to 350.
Line only the bottom of an 8-inch springform pan with aluminum foil; coat with non-stick spray and set aside. It's okay if aluminum foil hangs off the sides.
Combine crumbs, sugar, and salt.
Add melted butter and stir together.
Press the crumb mixture evenly on bottom and up the sides of the prepared springform pan.
Bake for 12 to 15 minutes, or until browned and crisp.
Add chocolate on top; breaking it up as needed to fit.
Put back in the oven for 2 minutes.
Spread the chocolate with an offset spatula until the entire crust is covered with chocolate.
Let cool for 20 minutes.
In the meantime prepare the Marshmallow Frosting.
In a small mixing bowl beat egg whites and salt.
Gradually add sugar, and continue to beat until soft peaks form.
Microwave corn syrup on high for 1 to 1 1/2 minutes, or until boiling.
Slowly pour a stream of the corn syrup over the egg whites, beating until mixture is stiff and glossy.
Add vanilla and beat until thoroughly combined.
Set the broiler on HIGH.
Slowly add and spread the marshmallow frosting on top of the chocolate. You may not need to use all of the frosting, especially if the chocolate was still warm when you tried to add the frosting.
Spread the frosting evenly across the top, sprinkle with turbinado sugar, and place the tart under broiler.
Broil for 3 minutes, or until top is browned and crispy.
Remove from oven.
Allow to set; about 3 to 4 hours.
Remove the ring of the springform pan, cut and serve.