Begin by soaking your cashews in a bowl of hot water for about 10 minutes. This will soften them quicker than cool water.
Zest the lemon with a microplane and set aside the zest. Grate the garlic with the microplane and set aside with the lemon zest.
Drain the cashews and add them to a small blender. Add in 3/4 cup of water, the juice from the lemon, and the 1/2 tsp of salt. Blend until smooth, add an additional 1/4 cup of water as needed. You want the consistency to be like heavy cream, thick but pourable. Season with more kosher salt and black pepper to taste. Set aside.
In a high-sided sauté pan, add in the chili oil and bring it to medium heat. Ad the breadcrumbs and sumac and toast until golden and crisp. Season with a pinch of salt and set aside. Wipe out the pan.
Put the pan back on medium heat, add the butter and olive oil and let the butter fully melt. Add in the garlic, lemon zest, za'atar seasoning and red pepper flakes and stir for 1-2 minutes or until fragrant. Turn the heat down to low and continue to cook.
At the time, cook your pasta noodles in salted water according to package instructions. Remove the noodles with a slotted spoon about 1 minute before they are fully "done" and reserve a cup of warm pasta water.
Add the cashew cream to the pan with the za'atar mixture. Stir to combine, it won't look completely smooth at first, but trust the process!
Add the pasta directly to the sauce, stir gently to make sure the pasta gets coated in the sauce. Separate any big pasta pieces that might have stuck together.
Add splashes of pasta water into the pan as you mix, this will help the sauce become smooth and it will begin to cling to the pasta.
Remove the pan from the heat and spoon the pasta onto your plates. Top with a scattering of the breadcrumbs and with any za'atar you have on hand. Serve immediately!