Preheat oven to 325 Fahrenheit. Grease the bottom of a 8x8 -inch baking pan with butter or line it with parchment paper; set aside.
For the base:
In a food processor, add 9 sheets honey graham crackers and pulse into fine crumbs. Add ¼ cup melted unsalted butter and pulse a couple of times to fully incorporate. Pour into the lined baking pan and gently pat down evenly with hands or base of measuring cup. Bake for 5 mins. Remove from oven.
For the cheesecake:
Place the 2 (8-ounce) softened cream cheese and ¾ cup granulated sugar in a stand mixer. Beat for 2 minutes until light and fluffy. Add 2 large eggs one at a time, beating in between. Lastly, add 1 teaspoon pure vanilla extract and beat to combine until the mixture is smooth and lump free. Pour mixture onto the baked graham cracker crust and smooth into a single layer. Drop large spoonfuls of Nutella on top of filling and swirl gently with a knife.
Heat ⅓ cup nutella in the microwave for 30 seconds so that it is smooth. Drop large spoonfuls on top of the cheesecake layer and gently swirl with a knife.
Bake 30 minutes or until the center only slightly jiggles. Remove from the oven and cool completely then refrigerate for at least 3 hours (or freezer for 1 hour). Once set, remove from pan using the parchment lining and slice into 9 bars.