This chocolate cheesecake recipe has a simple brownie bottom and a cheesecake top. You need to let this sit in the refrigerator for at least 4 hours before you eat it so plan to make early in the morning or the day ahead of when you will want it.
Preheat the oven to 325°F.
Grease and lightly flour a 9-inch springform pan.
Melt the chocolate and butter in a medium sized pot over low heat on the stove top. Stir to combine, then add the sugar and mix well.
Remove from the heat.
Use an electric mixer to beat in the eggs, one at a time, mixing on low speed after each addition.
Add the milk and vanilla and mix well.
Combine flour and salt together, then gradually
add to chocolate mixture, mixing after each addition just until blended. Stir in the nuts if using.
Spread evenly into the prepared pan.
Place into the oven and set the timer to bake for 25 minutes. At the end of the 25 minutes, you will add the cheesecake layer.
While the cake bottom is baking, beat the cream cheese, sugar and vanilla in large bowl with electric mixer on medium speed until well blended.
Add sour cream and mix well.
Add the eggs, one at a time, mixing on low speed after each addition just until blended.
Remove the partially baked brownie from the oven at the 25 minute mark and pour the cheesecake mixture over brownie layer.
Return to the oven and bake for 50 to 60 minutes or until center is almost set.
When you remove from the oven, run a knife or metal spatula around rim of pan to loosen cake.
Leave in the pan, let cool to room temperature then place into the refrigerate at least 4 hours or overnight.
Before you serve, let the cake stand at room temperature for 30 minutes.
Remove the springform pan and dust the top with cocoa powder. Slice and serve.
Store leftover cheesecake in refrigerator.