Step 1: Preheat your oven to 325°F (160°C). In a medium bowl, mix the crushed cookies and melted butter until combined. Press the mixture firmly into the bottom of a 9-inch springform pan and bake for 10 minutes, then let it cool.
Step 2: In a large bowl, beat the room-temperature cream cheese and sugar together until smooth and creamy. Be careful not to overmix to avoid adding too much air.
Step 3: Add the sour cream, dark cocoa powder, and vanilla extract to the cream cheese mixture, blending on low speed until fully incorporated.
Step 4: Add the eggs one at a time, mixing just until combined after each addition. Pour the batter over the prepared crust and smooth the top.
Step 5: Bake for 50-60 minutes or until the edges are set but the center still has a slight jiggle. Turn off the oven and leave the door slightly ajar for 30 minutes to cool slowly.
Step 6: Once the cheesecake is room temperature, melt the white chocolate chips. Pipe 4-5 concentric circles on top of the cheesecake. Use a toothpick to drag lines from the center out to the edges to create the spider web effect.
Step 7: Chill the cheesecake in the refrigerator for at least 6 hours, or preferably overnight, before serving.