Preheat the oven to 350 degrees Fahrenheit.
Season a large stockpot of water with 1/2 tsp of salt. Bring it up to a boil. Once it is at a rolling boiling add in the pasta. Give it a one time stir to ensure the pasta isn’t stuck together.
Once it's back up to a rapid boil, set a timer and cook the pasta for 6 minutes.
Drain and rinse off the pasta with cold water until the pasta is completely cooled down. Set aside.
In a high-powered blender, add the soaked cashews, nutritional yeast, miso paste, lemon juice, apple cider vinegar, salt, and pepper, and blend until extremely smooth. Scrape down the sides of the blender as needed. Set aside.
Shred your vegan cheese blocks and combine the two to create a blend. Set aside.
In a large, deep pot, over medium heat, melt the vegan butter.
Once melted, add in the flour, stir well and continuously, with a wooden spoon, cooking for about 1 1/2 minutes.
With a whisk, slowly whisk in the cashew milk, about 1/2 a cup at a time. The sauce should be very smooth.
Once all of the cashew milk has been added, add in that cheese paste we blended from earlier. Whisk together really well until combined.
Cook the sauce for about 2 minutes or until it begins to bubble.
Now turn the heat down to medium-low, add 2 1/2 cups of the shredded cheese blend, and whisk it all together. Continue cooking until most of the cheese has melted into the sauce. A little bit of texture is okay.
Add the cooked pasta in, turn the heat off, and stir very well to coat the pasta evenly in the sauce.
Add in 1 cup more of the shredded cheese blend and stir well.
Pour the vegan mac and cheese into an 8x8 inch baking dish of choice, scraping in all of the sauce. With a rubber spatula, flatten the mixture out from corner to corner. *I always place my baking dish on a sheet pan just in case the mac and cheese ooze over.
Sprinkle evenly on top the last bit of the shredded cheese blend.