Bring a large pot of salted water to a boil and cook 8 ounces of dry pasta according to package instructions until al dente, typically 8-12 minutes. Reserve about a cup of pasta water, then drain and set aside.

In a blender or food processor, combine 1 large ripe avocado, 2 tablespoons of olive oil, 1.5 cups of basil, 1 cup of spinach, 3 cloves of garlic, and 0.25 cup of cashews. Add 2 tablespoons of lemon juice, 0.5 teaspoon of salt, and 0.25 teaspoon of black pepper.

Blend the mixture on high until smooth, about 1-2 minutes. If too thick, add a splash of reserved pasta water.

Taste and adjust seasoning as needed, blending briefly to incorporate any changes.

In a large bowl, mix the drained pasta with the avocado pesto, adding reserved pasta water a little at a time until desired consistency is reached.

Serve immediately, garnished with halved cherry tomatoes and a drizzle of olive oil if desired.