Step 1

Preheat the oven to 325F. Lightly grease a 9 or 10-inch springform pan.

Step 2

Combine the chocolate and butter in a saucepan or in a microwave-safe bowl. Melt over low heat (on the stovetop) or on 50% power in the microwave at 1-minute increments, stirring in between.

Step 3

Cool the mixture to lukewarm, then whisk in the sugar until smooth.

Step 4

Add the eggs one at a time, blending well after each addition. Mix in the vanilla and salt. Add the flour and mix until just combined.

Step 5

Pour the batter into the prepared pan and smooth. Bake for 30-35 minutes, until the cake just rises in center (a tester inserted into center will not come out clean) and springs back lightly to the touch.

Step 6

Cool the cake in the pan completely (the center may fall which is normal).

Step 7

Melt the chocolate - over low heat (on the stovetop) or on 50% power in the microwave at 30-second increments, stirring in between.

Step 8

Pour the melted chocolate into the bowl of a stand mixer. Add the powdered sugar, cream cheese and vanilla and mix until completely smooth, scraping down the sides and bottom 1-2 times.

Step 9

With the mixer running on low, slowly pour in the heavy cream. Scrap down the sides and bottom of the bowl, then increase the speed of the mixture to medium-high and whip until light and fluffy, about 3-4 minutes.

Step 10

Spread the mousse on top of the cooled chocolate cake. Cover and refrigerate for at least 6 hours or up to 1 day.

Step 11

Using an electric mixer, beat the cream and powdered sugar in a medium bowl until soft peaks form. Spread the whipped cream over the cake. Dust with grated chocolate, if desired. Chill for up to an hour or serve immediately.