Cut the squash in half and remove seeds. Place on a backing sheet, cut side down. Add water to cover the bottom of the pan. Place in preheated oven and back for 30 to 40 minutes, until soft.
Pesto Prep
Place the rest of the ingredients, except the olive oil, into a food processor. Blend them all together until they start to combine.
Add the olive oil and blend until desired smoothness.
Serve on top of the spaghetti squash, or blend it all in–whichever your preference.