Grease a 10 1/2-inch springform pan and set aside.
Brownie Bottom:
Follow the instructions on the box, the ingredients amounts may differ.
Add brownie batter to a greased 10 1/2x3-inch springform pan.
Bake for 15-20 minutes, until the top is set, but not fully baked.
Cheesecake:
Beat cream cheese, sugar, flour, and vanilla with an electric mixer until fluffy.
Add eggs and egg yolks, beating on low speed just until combined.
Stir in sour cream and lemon zest.
Pour cheesecake batter into pan over the brownie bottom. Spread with a spatula.
Scoop the raspberry sauce or preserves onto the cheesecake batter and gently stir to combine.
Bake at 325 degree F for about 1-1/2 hours or until center appears nearly set and does not giggle when shaken.
Cool for 15-20 minutes and using a knife loosen crust from sides of pan. Cool 30 minutes more, remove sides of pan.
Cool completely before adding the chocolate ganache.
Chocolate Ganache:
Add chocolate and corn syrup to a medium bowl.
Pour hot heavy cream over the chocolate, let stand for 1 minute and using a spatula stir to combine. Stir well until all the chocolate melts and the mixture is shiny and smooth. If needed, microwave for 30 seconds to melt any remaining small lumps.
Let cool to room temperature, but not to harden.
Pour chocolate ganache over the cheesecake and distribute evenly using a spatula. Garnish with fresh raspberries.