Spray a 9x13 in metal baking pan with nonstick cooking spray and preheat the oven to 350°. In a large bowl whisk the granulated sugar, eggs, vanilla extract, buttermilk and vegetable oil. Add in the flour, cocoa powder, baking soda and salt and whisk until combined. Add in the coffee last and whisk until everything is incorporated.
Pour the cake batter into the prepared pan and bake for 30-35 minutes, or until the cake is baked through. Remove from the oven and allow to cool completely.
Once the cake has cooled, flip the cake out onto a baking sheet and trim any crispy edges off. Add the cake to the bowl of a stand mixer fitted with the paddle attachment and add in ¾ of the jar of Nutella. Mix on low to incorporate. You want the mixture to stick together but not be too moist. Add in more Nutella to reach desired consistency.
Line a baking sheet with parchment or was paper. Use a medium sized cookie scoop (about 2 tbsp each) to scoop each cake ball. Roll in your hands to create a ball and place on the prepared baking sheet. Repeat and evenly space. Place the pan in the refrigerator and chill for at least 1 hour.
Once you're ready to assemble, melt the chocolate wafers in a heat proof bowl for 30 seconds at a time, stirring in between, until completely melted. Remove the cake balls from the fridge. Dip ¼ inch of the popsicle stick into the melted chocolate and press into the base of the cake ball, about 3/4 of the way through. Dip the full cake pop into the chocolate covering the entire ball. Hold above the bowl of chocolate to allow excess chocolate to drip off.
Set the cake pops upright into a cake pop stand or a piece of Styrofoam and, while the chocolate is still wet, sprinkle the top with a generous amount of sprinkles. Repeat until all the cake pops are coated and topped with sprinkles. Allow to dry completely. You can enjoy immediately or store in an air tight contained at room temperature for up to one week.