Line the bottom of a 9-inch springform pan with parchment paper. Press the cookie crumbs and melted butter mixture firmly into the bottom. Freeze for 15 minutes. 2. Spread the softened vanilla ice cream evenly over the crust. Freeze for at least 2 hours until firm. 3. Spread the softened chocolate ice cream over the vanilla layer. Smooth the top with an offset spatula. Freeze for at least 4 hours, or overnight. 4. Make the ganache drip: In a microwave-safe bowl, combine heavy cream, chocolate chips, corn syrup, and salt. Microwave in 20-second bursts, stirring after each, until smooth. Let cool to 90°F (32°C) — it should be thick but pourable. 5. Remove the cake from the pan and place on a serving plate. Pour the ganache over the center, letting it drip down the sides. Work quickly. 6. Immediately sprinkle the almonds or sprinkles around the top edge. Freeze for 30 minutes to set the drip. 7. Slice with a hot knife (dip in hot water, wipe dry) for clean cuts. Serve straight from the freezer.