Place ½ cup of raw cashews in a small bowl and cover them with boiling water. Soak them for 15 minutes.
To make the bacon bits, preheat the oven to 400 F (200 C). In a small baking dish, combine 1 teaspoon miso paste, 1 ½ teaspoons liquid smoke, and 1 teaspoon soy sauce. Add the hemp seeds and mix well. Bake for 15 minutes, stirring the bacon bits a few times. They should be brown, but not burned. Remove them from the oven and give the bottom of the baking dish a sweep with a spoon to pick up any stuck-on hemp seeds. Set aside.
Note on the pasta: The sauce takes about 15 minutes to make. Start the pasta right after adding the hemp seeds to the oven.
Heat a skillet or frying pan over medium-high heat. When the pan is hot, add the onions and ½ cup of vegetable broth. Simmer the onions until they are soft and all the vegetable broth is absorbed (about 10 minutes). Add the garlic and stir for 30 seconds. Then, remove the pan from the heat.
Drain the soaked cashews, placing them in a blender or food processor. Add the cooked onions and garlic, 2 cups of vegetable broth, 1 teaspoon miso paste, 2 tablespoons nutritional yeast, and 1 tablespoon lemon juice. Blend until the sauce is smooth and creamy.
Return the sauce to the frying pan and add the sundried tomatoes. Heat the sauce to let the tomatoes soften for a minute or two, then stir in the chopped spinach and ⅓ cup bacon bits. Wilt the spinach for 1-2 minutes. Add more vegetable broth if the sauce is too thick.
When you drain the pasta, reserve 1 cup of the cooking water. Mix the cooked pasta into the pan. If the sauce is too thick, add vegetable broth, a little at a time, to thin it.