Preheat oven to 400.
Cut off the very top of a head of garlic. Drizzle with oil, sprinkle with salt and loosly wrap in foil.
Place directly on oven rack and roast for 45 minutes - 1 hour. Bulb will be golden brown. Unwrap and let cool
At 40 minute mark, bring 10 cups of water to a boil and add salt. Once boiling, add pasta and stir 8-10 minutes.
Drain pasta and set aside.
Heat a large oven safe skillet over medium heat. Add oil and minced fresh garlic. Stir and cook for 1-2 minutes or until light golden brown. Immediately add arrowroot flour and whisk cook for 1 minute.
Slowly add almond milk while whisking, then cook for 2 minutes over medium heat, stirring frequently. The sauce will be a little clumpy.
Transfer mixture to a blender, along with the roasted garlic.
Add 1/4 tsp salt and pepper, yeast and parmesan cheese. Blend on high until creamy and smooth.
Taste, and if needed, add more salt, pepper and cheese.
Return sauce to skillet and cook over low heat until warmed and slightly thickened - 2-3 minutes, whisking occasionally. If you need to thin it, add almond milk 1 Tbsp at a time. If it bubbles too aggressive,
Turn off heat.
Add cooked pasta and toss to coat. Top with 1 Tbsp parmesan cheese.