Start by lining your 9x9 inch baking dish with parchment paper, leaving some overhang on the sides.
In a mixing bowl, combine the sugar-free Nutella, blanched hazelnuts, pumpkin seeds, and sunflower seeds. Use a spatula to mix everything together until well-combined.
Spoon the Nutella mixture into the prepared baking dish. Press it down firmly to create an even layer.
In a double boiler or microwave, melt the dark chocolate until smooth.
Once melted, drizzle the chocolate over the Nutella layer in the dish. Use a spatula to spread it evenly if desired.
Place the dish in the refrigerator for about 1-2 hours, or until the bars are firm enough to cut.
Once set, lift the bars out of the dish using the parchment paper overhang. Cut them into squares or rectangles and serve chilled.
