Crank the oven to 325ºF.
Take the flour, cinnamon, baking soda, baking powder, and salt for a spin in your food processor, then move them to a large mixing bowl.
Spin the sugar, oil, eggs, and vanilla in the processor, pulsing just a few times to bring everything together, then add the wet mixture to the bowl with the dry ingredients and stir to combine. Don't worry if there are a few lumps.
Install the processor's shredding blade and shred the butternut squash in the food processor. Dump onto a kitchen towel and, over the sink, twist into a ball to wring out as much water as possible. Fold the squash and the pumpkin seeds into the batter using a large rubber spatula, or, better yet, your hand.
Pour into a nonstick 9-by-5-by-3-inch loaf pan or a standard nonstick muffin pan, filling the latter two-thirds full. If you don't have a nonstick pan, lightly butter and dust the pan with flour before adding the butter.
Bake the loaf for 1 hour and 15 minutes to 1 1/2 hours, or until it reaches an internal temperature of 200 to 210ºF. Cool for 15 minutes in the pan, then turn out onto a cooling rack to cool completely. For muffins, bake for 30 minutes, then remove from the muffin tin to a cooling rack immediately.