Place a large pan of well salted water over a high heat and bring to a boil. Cook the linguine until al dente, approximately 10 minutes.
Meanwhile start to prepare the sauce. In a saucepan melt the margarine over a low heat. Add the garlic and sauté for a minute, being careful not to let the garlic burn.
Add the oat milk, onion powder, nutritional yeast, black pepper and two tablespoons of the pasta water.
Bring to a light boil, whisk and then simmer for 5 minutes until the sauce has slightly thickened.
Return to the pasta. Add the frozen peas in the final minute of cooking and then drain the pasta and peas. Once drained, return the pasta and peas to the saucepan. With the heat off, stir through the spinach until it has wilted.
Pour over the sauce, rinsed capers and extra virgin olive oil.
Stir until the ingredients are well combined and the sauce has coated the pasta. Taste and season with salt, pepper and nutritional yeast as needed.