01 - Preheat oven to 325°F. Line the bottom of a 9-inch springform pan with parchment paper.
02 - Pulse chocolate cookies in a food processor until finely crushed. Combine with melted butter. Press firmly into the bottom of the pan. Bake for 10 minutes. Cool slightly.
03 - In a large bowl, beat cream cheese and sugar until smooth. Add eggs, one at a time, mixing well after each. Blend in sour cream and vanilla. Whisk strawberry puree with cornstarch, then fold into the batter.
04 - Pour filling over cooled crust. Smooth the top. Bake for 50 to 60 minutes, or until the center is just set and slightly wobbly. Turn off oven, crack the door, and let cheesecake cool inside for 1 hour.
05 - Remove from oven and run a thin knife around the edge to loosen. Cool to room temperature, then refrigerate for at least 4 hours, preferably overnight.
06 - Heat heavy cream until just simmering, pour over chopped chocolate, and let sit 2 minutes. Stir until smooth. Let cool slightly, then spread over chilled cheesecake.
07 - Top with fresh strawberries. Drizzle with melted dark chocolate if desired. Chill 30 minutes before slicing.