01 -
Heat your oven to 165°C. Grease a 23 cm springform pan or put parchment paper in it. Mix graham cracker bits, sugar, melted butter, and cocoa powder in a bowl until it looks like damp sand. Push it down hard on the pan bottom. Bake it for 8-10 minutes till it's golden. Take it out and let it cool down.
02 -
Beat the soft cream cheese and sugar with a mixer until it's smooth. Add eggs one by one, mixing well each time. Keep scraping the bowl sides. Mix in vanilla, then slowly add the cooled melted chocolate. Gently fold in sour cream till it's all mixed up. Pour this mix onto your cooled base and smooth the top flat.
03 -
Put it in your hot oven for 55-60 minutes. The sides should look done but the middle should wobble a bit. Switch off the oven, open the door a crack, and leave the cake in there for an hour. This stops cracks from forming. Take it out and let it cool completely.
04 -
Put raspberries, sugar, lemon juice, and cornstarch (if using) in a small pot. Cook on medium heat for 5-7 minutes, stirring now and then, until berries break down and it gets thick. Take it off the heat and cool it down. You can strain out seeds if you want it smoother.
05 -
After the cake cools, spread the berry mix all over the top. Cover it with plastic wrap and put it in the fridge for at least 3 hours, but overnight works better. This helps it set right and tastes better too.
06 -
When you're ready to eat, take the cake out of the pan carefully. Put fresh raspberries, chocolate bits, and whipped cream on top. Cut it with a sharp knife dipped in hot water and wiped clean between slices for neat pieces.