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.
05 - Turn off oven, crack the door, and let cheesecake cool inside for 1 hour. 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.