Preheat the oven to 375 degrees. Lightly grease an 8" round cake pan; cut a piece of parchment or waxed paper to fit, grease it and lay it in the bottom of the pan.
To make the cake: Put the chocolate chips and butter in a microwave safe bowl and heat until the butter is melted and the chips are soft. Stir until the chips melt, reheating briefly if necessary. You can also do this over a burner set at very low heat. Transfer the melted chocolate/butter to a mixing bowl.
Stir in the sugar, salt and vanilla.
Add the eggs, beating briefly until smooth. Add the cocoa powder and mix just to combine.
Spoon the batter into the prepared pan.
Bake the cake for 20-25 minutes; the top will have formed a thin crust,and it should register at least 200 degrees on an instant read thermometer if using.
Remove cake from the oven and allow it to cool in the pan for 5 minutes.
Loosen the edges of the pan with a table knife or nylon spatula, and turn it out onto a serving plate. The top and edges may crumble a bit - no worries - the glaze will cover all! Allow the cake to cool completely before glazing.
To make the glaze: Combine the chocolate and cream in a microwave safe bowl, and heat until the cream is very hot, but not simmering. Remove from the microwave and stir until the chocolate melts and the mixture is completely smooth.
Spoon the glaze over the cake, spreading it with a rubber spatula to drip over the sides a bit. Allow the glaze to set for several hours before serving the cake.