Grease the sides of the pan with oil spray after baking the crust.
Melt the chocolate in the microwave in 15-second intervals, stirring in between. Set aside to cool.
Beat the cream cheese at medium speed for 3 minutes until creamy.
Add brown sugar, granulated sugar, cocoa powder, and espresso powder (if using). Beat for another 2 minutes.
Scrape the bowl and beat for another 30 seconds.
Mix in the sour cream and scrape the bowl.
Add the melted chocolate and mix.
Add eggs one at a time, mixing just until combined. Scrape the bowl as needed.
Mix in vanilla and salt briefly.
Pour the batter over the cooled crust and spread evenly.