• Preheat the oven to 325°F (163°C).
• Grease a 10-inch springform pan and set aside.

Brownie Bottom:

• Prepare the brownie mix according to the package instructions, using the eggs, water, and vegetable oil.
• Pour the brownie batter into the greased springform pan.
• Bake for 15-20 minutes, until the top is set but not fully baked. Remove from oven and let cool slightly.

Cheesecake Layer:

• In a large mixing bowl, beat the softened cream cheese, sugar, flour, and vanilla extract with an electric mixer until fluffy.
• Add the eggs and egg yolks one at a time, beating on low speed just until combined.
• Stir in the sour cream and lemon zest.
• Pour the cheesecake mixture over the brownie bottom in the pan.
• Drop spoonful's of raspberry preserves or sauce onto the cheesecake batter and gently swirl with a knife or spatula.

Baking:

• Bake at 325°F for about 1 1/2 hours, or until the center appears nearly set and does not jiggle when shaken.
• Cool in the pan on a wire rack for 15-20 minutes, then use a knife to loosen the crust from the sides of the pan. Remove the sides of the pan and allow to cool completely.

Chocolate Ganache:

• Place the chopped chocolate and corn syrup in a medium bowl.
• Pour the hot heavy cream over the chocolate and let stand for 1 minute. Stir with a spatula until the chocolate is completely melted and the mixture is smooth and shiny. Microwave for 30 seconds if there are any remaining lumps.
• Let the ganache cool to room temperature so it thickens slightly but is still pourable.
• Pour the ganache over the cooled cheesecake, spreading it evenly with a spatula.

Garnish and Chill:

• Garnish the cheesecake with fresh raspberries.
• Refrigerate the cheesecake for 4 to 24 hours to set completely.