Preheat the oven to 350 degrees Fahrenheit.
Fill a large stockpot with water. Season it with 1/2 teaspoon kosher salt. Once it is at a rolling boil, 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 softened cashews, nutritional yeast, miso paste, lemon juice, apple cider vinegar, salt, pepper, and blend until extremely smooth. Scrape down the sides of the blender as needed. Set aside.
Shred the vegan cheese blocks and combine the two to create a blend. Set aside.
Place a large, deep stockpot over medium heat and 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.
Turn the heat off and add the cooked pasta in. Stir very well to coat the pasta evenly in the sauce.
Add in the rest 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 like to place my baking dish onto a sheet pan just in case the mac and cheese ooze over.
Wrap the top of the dish with tin foil and bake it on the middle rack for 30 minutes.
Allow to completely cool at room temperature and then place in the refrigerator to chill overnight. Chilling this will solidify the mac and cheese and make it easy to roll into balls.