In a blender, combine the coconut milk, basil leaves, green onion, cilantro, brown sugar, ginger, garlic powder, coconut aminos, rice vinegar, allspice, sesame seeds, sesame oil, and Thai red peppers. Blend until smooth and creamy, which should only take about 1-2 minutes.

Cut the chicken into 1-inch cubes and place it in a large bowl. Pour the prepared marinade over the chicken, ensuring each piece is well-coated. Cover the bowl and refrigerate for at least 2 hours, or ideally overnight.

In a mixing bowl, combine the chopped basil, sesame seeds, crushed roasted cashews, and lime zest. Stir until evenly distributed.

Preheat your grill to medium-high heat, about 350°F. While the grill heats, thread the marinated chicken pieces onto soaked wooden skewers. Lightly oil the grill grates and place the skewers on the grill, brushing occasionally with remaining marinade.

In a small saucepan, melt plant-based butter over medium heat. Add a small amount of water and whisk in the cashew butter, reserved coconut milk, minced Thai red pepper, brown sugar, rice vinegar, ginger, garlic powder, and allspice. Cook for about 4-5 minutes, or until the sauce thickens.

Once the Thai Spicy Basil Chicken Skewers are beautifully charred and cooked through, remove them from the grill. Serve immediately on a platter, sprinkled with the prepared gremolata and drizzled with the creamy cashew sauce.