Drain and rinse the spaghetti with plenty of water. Set aside.
Wash the arugula and trim the thick stalk ends.
To blanch: add arugula batches to boiling water. Submerge in water for about 10 seconds and remove with a slotted spoon. Transfer the hot arugula to ice water bath and submerge. Use your hands to squeeze out the water from the arugula and set aside.
Roughly chop the almonds and toast them lightly.
Combine the arugula, almonds, garlic, parmesan cheese and salt in the bowl of a food processor. Pulse, until coarsely pureed. With the motor running slowly drizzle in the olive oil. Continue to process until smooth and creamy. Taste and adjust salt and pepper as needed.
Add drained spaghetti to boiling water and boil for 3 minutes.
Drain the spaghetti, transfer to a large bowl and combine with the pesto.
Garnish with additional arugula, dried tomatoes and Parmesan cheese if desired. Serve.