Add spaghetti squash and eggs to a food processer and pulse until smooth.
Transfer squash mixture to a bowl and add flour, sugar, vanilla, baking powder, and salt. Stir with a fork until combined.
Heat butter in a nonstick skillet over medium heat. Scoop batter onto the skillet, about ½ cup per pancake. Add blueberries on top of the batter. Cook 5-7 minutes per side.