In a food processor grind the graham crackers until they are broken into a fine powder. Add the butter, nutella, brown sugar, salt and cocoa powder and process until it is all well incorporated. You may have to scrape down the sides of the bowl a few times.
Press the crust evenly into the bottom of an 8 or 9-inch spring form pan. It should come up the sides slightly.
Prepare the Strawberry topping:.
In a sauce pot add the strawberries, sugar, and 2 tablespoons of water. Cook over medium heat until the strawberries are quite soft. Use an immersion blender to puree the fruit. (You can also do this by pouring the strawberries into a regular blender, then return to the pot to finish cooking.).
Sprinkle the gelatin over 2 tablespoons of cold water in a small bowl. Allow it to sit for about 1 to 2 minutes.
Transfer the gelatin to the strawberries and gently cook over low heat.
Whisking just until the gelatin is completely dissolved. Remove from heat. Reserve 3/4 cup of the strawberry mixture for the top layer of the cake.
To make the cheesecake:.
In a stand mixer beat the cream cheese and sugar on medium-low speed, using the paddle attachment, until smooth. Add the vanilla extract. Add the strawberry topping, except the 3/4 cup you have reserved for the top layer.
In a separate bowl whip the heavy cream until medium peaks. Fold the whipped cream into the strawberry cheesecake batter. Gently folding just until it is all combined.
Pour the cheesecake into the prepared pan. Tap the pan gently on the counter to bring any air bubbles to the surface. Let it sit, uncovered, in the refrigerator for about 2 hours or until it is set to the touch.
Once the cheesecake is set, pour the remaining 3/4 cup strawberry topping over it. If the topping has set up in the pot, gently heat it for a minute, just until it is pourable.
Place the cheesecake back into the refrigerator and allow to set, uncovered, for another 30 minutes, or until the topping is set. At this point it is ready to serve or you can cover the cheesecake with plastic and it can sit in the refrigerator for 24 hours.
Before unlocking the spring form pan, run a knife around the edge of the cheesecake to loosen it. Top with the fresh strawberries.