Preheat your oven to 350°F (175°C). Line a loaf pan with parchment paper for easy removal.
Toast the hazelnuts in a dry skillet or oven until fragrant and golden, then roughly chop and set aside to cool.
In a large mixing bowl, whisk together the flour, sugar, baking soda, cinnamon, nutmeg, and salt until well combined.
In a separate bowl, beat the eggs, then stir in the pumpkin puree and vegetable oil until smooth and combined.
Pour the wet mixture into the dry ingredients and gently fold until just combined; do not overmix to keep the batter tender.
Stir in the toasted hazelnuts, distributing them evenly throughout the batter.
Pour the batter into your prepared loaf pan, smoothing the top with a spatula.
Bake in the preheated oven for about 60 minutes, or until a toothpick inserted in the center comes out clean and the loaf is golden brown.
While the bread bakes, prepare the cinnamon sugar topping by mixing melted butter, sugar, and cinnamon in a small bowl.
Once baked, transfer the bread to a cooling rack and brush the top with the melted butter mixture, then sprinkle evenly with cinnamon sugar for a crunchy, flavorful top.
Let the bread cool slightly before slicing. Enjoy the moist, tender crumb with a crunchy nut topping and sweet cinnamon accents.