Step 1: Preheat oven to 325°F (preheated oven). In a food processor, pulse chocolate sandwich cookies into fine crumbs. Mix with melted butter, then press into the bottom of a 9-inch springform pan. Bake for 10 minutes, then let cool.
Step 2: In a medium saucepan, combine evaporated milk, brown sugar, butter, and egg yolks over medium-low heat. Cook, stirring constantly, until thickened (about 5–7 minutes). You'll know it's thick enough when it coats the back of a metal spoon.
Step 3: Remove from heat and stir in vanilla extract, salt, shredded coconut, and pecans. Let cool slightly.
Step 4: Spread ¼ to ⅓ of the coconut pecan topping evenly over the crust. Cover the remaining and refrigerate until ready to frost the cheesecake.
Step 5: Melt chopped bittersweet chocolate and a portion of the heavy cream in the microwave at a low power for 30 seconds to 1 minute, stopping the microwave to stir every 20 seconds until just fully melted.
Step 6: In a large bowl, beat the cream cheese and sugar on low speed until smooth. It's important to scrape down the sides of the bowl after every step of this process.
Step 7: Mix in Dutch process cocoa powder, vanilla extract, and salt.
Step 8: Mix in sour cream and heavy cream until fully combined.
Step 9: Add eggs one at a time, beating briefly after each addition.
Step 10: Mix in melted chocolate until fully combined.
Step 11: Pour the cheesecake filling over the prepared crust and topping layer. Place the pan, wrapped in aluminum foil to prevent water from seeping into the pan, in a water bath and bake at 325°F for 1 hour 15 minutes to 1 hour 30 minutes, or until the center 2-3 inches still has a slight jiggle. Turn off the oven and let the cheesecake cool inside for 1 hour with the door slightly ajar before transferring it to a wire rack. Once at room temperature, cover the cheesecake in plastic wrap and refrigerate it for a minimum of 4 hours, preferably overnight.
Step 12: Once the cheesecake has chilled for at least 4 hours, spread the remaining coconut pecan topping evenly over the top. For an extra touch, drizzle with chocolate ganache or chocolate sauce and extra coconut flakes before serving! Slice and enjoy!