Soak cashews in water overnight in the refrigerator or place in boiling water for 10 minutes, in order to soften. If you have a high speed blender, you can skip this step. Drain the cashews, discard the soaking water, and add them to the blender along with 1 cup of fresh water. Blend on puree until the mixture is very smooth. Periodically stop the blender to scrape down the sides and to check the texture. This could take a while, depending on the power of your blender.
While the cashews are processing in the blender, prepare the pasta according to the package directions making sure to salt the water.
Lightly scrub the four lemons to remove any soil, before zesting them. Zest all four lemons, then juice all four lemons.
Add the vegan butter to a large pan and melt. Add the lemon zest, bring to a boil and let bubble for a couple of minutes. Add the lemon juice and let the mixture simmer until it is reduced and begins to thicken, about five minutes. Add the coconut milk and bring back to a low boil. Stir as the mixture simmers and reduces until it coats the back of a spoon. Add the cashew mixture, nutritional yeast, the turmeric, the salt, and the pepper. Stir to combine. If the texture is not totally smooth, return the entire mixture to the blender and process for a couple of minutes until it is silky.
Spoon the sauce over the pasta and sprinkle on about a tablespoon of capers. Enjoy!
