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 addition. Blend in sour cream and vanilla.
04 - Whisk strawberry puree with cornstarch until smooth, then fold into the cream cheese batter.
05 - Pour filling over cooled crust. Smooth the top. Bake for 50 to 60 minutes, or until the center is just set and slightly wobbly.
06 - Turn off oven, crack the door open, 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.
07 - Heat heavy cream until just simmering, then pour over chopped chocolate. Let sit for 2 minutes, then stir until smooth. Let cool slightly.
08 - Spread ganache over chilled cheesecake. Top with fresh strawberries. Drizzle with melted dark chocolate if desired. Chill for 30 minutes before slicing.