Preheat oven to 400 degrees.
Slice delicata squash length-wise, remove and discard the seeds with a spoon, then slice length-wise one more time for four long slices per squash. Repeat with the other squash.
Place squash on a baking tray and drizzle with olive oil, tossing the squash with your hands to coat evenly. Place all squash cut side up, then sprinkle with sea salt and black pepper.
Bake for 25-30 minutes, depending on how soft you like your squash to be.
Toast the pumpkin seeds over medium-high heat for 3-4 minutes, or until then begin to pop and turn slightly golden. Immediately take off the heat and allow to cool.
Place the pumpkin seeds and all remaining ingredients in a food processor or blender and pulse to a fairly coarse texture and until all ingredients have combined.
Drizzle the rosemary pesto over the delicata squash spears!