In a large bowl, combine Oreo crumbs, brown sugar, salt, and melted butter. Stir.

Transfer the crumbs into a buttered 9" springform pan. Press the crumbs halfway up the sides and into the bottom of the pan tightly. Set aside.

Melt the chocolate in the microwave (stirring every 20 seconds), or melt in a saucepan on very low heat (stirring constantly). Set it aside while you work on the filling.

In a large bowl or stand mixer, combine softened cream cheese, powdered sugar, and cocoa powder. Mix until creamy, scraping down the bowl.

Pour the melted chocolate into the bowl. Add vanilla, salt, and sour cream to the bowl and mix well. Scrape down the bowl.

In a chilled bowl or stand mixer, add the chilled cream and whip to stiff peaks using a wire whisk attachment. Don't overmix or you will make butter!

Transfer the whipped cream into the cream cheese mixture and fold gently until fully incorporated.

Break up 1 cup of raspberries into smaller pieces if they're large, and add into the cheesecake mixture. Fold gently to mix.

Transfer the cheesecake filling into the prepared crust and smooth the top. Cover and refrigerate for at least 6 hours or preferably overnight. You can top it with ganache before or after chilling.

Heat cream in a small saucepan on low heat until it comes to a simmer.

Place the chocolate in a medium heat safe bowl. Pour the hot cream over the chocolate and let it sit for 5 minutes. Whisk until smooth and creamy.

Pour the chocolate ganache onto the cheesecake and spread until the edges, smoothing the top. Pop the cheesecake into the fridge or freezer for 5-10 minutes to set the ganache just enough to top with raspberries.

Take the ring off the outside of the cheesecake and arrange the rest of the raspberries on top in rings to cover the whole surface. Refrigerate to serve later or serve right away!