Recipe(tried): Brownie Bottom Cheesecake - Shaunda/NC You might want to try this as well.

Brownie Bottom Cheesecake
recipe by Nana Lee

This version takes a bit longer to make than the original, Recipe #143627, but it is worth it! It's best to make in a springform pan, a heartshaped springform pan for Valentie's day would be fantastic! This cake was originally named MURPHY'S BONZO CAKE and came from Razzeldazzle recipe site.
16 servings

FOR THE BROWNIE:
(or you could use your favorite brownie mix, mine is Duncan Hines, WITHOUT THE CHOC CHIPS. OR Girarhdelli(sp?), it has choc chips in it)
1/3 cup semi-sweet chocolate chips
1 1/3 cups granulated sugar
1 cup butter, melted
3 eggs
1 cup cake flour
3 tablespoons cocoa powder
FOR THE CHEESECAKE:
21 ounces cream cheese, at room temperature
3/4 cup granulated sugar
2 eggs
1 teaspoon vanilla extract
For the chocolate mousse
4 cups semisweet chocolate, chopped (56 percent)
10 pasteurized egg yolks
1/2 cup granulated sugar
3 cups heavy cream

To prepare the brownie:.
Preheat oven to 300 degrees F.
Line a 10" springform pan or a 10" baking pan with 3" sides with parchment paper and spray the sides with cooking spray.
In a large bowl, combine chocolate chips and sugar. Add melted butter and mix with an electric mixer for 2-3 minutes.
Add the eggs one at a time and stir after each addition until well-combined.
Sift the cake flour and cocoa and add to the mixture.
Scrape the sides of the bowl and beaters to combine.
Mix until it is a smooth paste.
Pour into the baking pan and bake for 45 minutes, or until the center springs back when pressed.
Let the brownie cool completely, then run a knife around the edges to loosen and remove from pan.
Turn upside down into a clean 10-inch baking pan with 3-inch sides lined with parchment or a similar size springform pan.

To prepare the cheesecake:
Preheat oven to 285 degrees F.
With an electric mixer, beat cream cheese. Add sugar and continue to mix.
Scrape the sides of the bowl and beaters to combine and eliminate lumps.
Add the eggs one at a time and stir after each addition.
Add vanilla extract and mix 1 minute.
Pour on top of the cooked brownie in cake pan.
Bake the cheesecake/brownie on a rimmed sheet or baking pan in a 1/2" water bath for 45 minutes.
The top should feel firm to the touch.
Let cool completely.
To prepare the chocolate mousse:.
In a double boiler or bowl over simmering water, melt the chocolate.
In a separate bowl, beat the egg yolks and sugar with an electric mixer until light and fluffy.
Slowly alternate the addition of cream and melted chocolate to the egg yolks.
Beat until soft peaks form.
Pour the chocolate mousse on top of the cheesecake (you might have some extra mousse).
Smooth the surface to avoid air pockets.
Refrigerate until the mousse sets, about 3 hours.
If not using a springform pan, run a knife around the edges to loosen.
Heat the bottom and the sides of the pan on the stovetop for a few seconds.
Turn it upside down on a piece of plastic and cardboard.
Shake the pan, and the cake should slowly come out.
Flip it back on a piece of cardboard or serving plate and remove the plastic.

NOTE: This part would be easier if using a springform pan.