Preheat the oven to 400 F and line a small baking sheet with parchment paper.

Wash the pumpkin and slice off the stem. Slice the pumpkin in half and scoop out the seeds. Drizzle with 1 tbsp of avocado oil and season with salt and pepper. Place the pumpkin flesh side down, and the skin side up on the baking sheet. Bake in the preheated oven for 30-40 minutes or until soft. Remove from the oven and allow to cool for 10 minutes before scooping out the flesh. Set aside.

Bring a large pot of well-salted water to a boil. Cook the pasta as directed until aldente, reserving 1/4 cup of pasta water. Strain the pasta and lightly toss with olive oil to prevent sticking.

Combine the almond milk, lemon juice, and arrowroot starch in a bowl and whisk well to combine. Place a pot on the stove and add the milk mixture along with salt, pepper, onion powder, garlic powder, cooked pumpkin, cream cheese, and nutritional yeast. Use an immersion blender to fully blend the sauce until smooth.

Set the stove to medium-low heat and allow the sauce to simmer for 10 minutes. The sauce should be thick. Add the pasta water and stir well before turning off the stove and adding the cooked pasta. Stir to combine and coat the pasta in the sauce.

Season further to taste and serve the mac and cheese topped with chives and bacon.