Start by pounding your chicken breasts until they are about 1/2 inch thick, then cut them into bite-sized pieces around 1 to 2 inches. Pat the pieces dry with paper towels to help the coating stick better.
In a food processor, pulse together the sweetened coconut flakes, roasted cashews, and panko breadcrumbs until you have a coarse, crumbly mixture. Transfer this to a shallow bowl. In another small bowl, mix salt, brown sugar, garlic powder, ginger powder, black pepper, onion powder, chili powder, and cayenne pepper into the coconut-cashew-panko blend.
Place 1/2 cup flour in a shallow bowl for dredging the chicken pieces. In a separate bowl, whisk together the egg, egg yolk, melted butter, coconut or olive oil, and soy sauce until smooth.
Dredge each chicken piece in the flour first, shaking off excess. Then dip it into the egg wash, ensuring it’s fully coated. Finally, press the chicken into the coconut-cashew-panko mixture, pressing gently to adhere the coating well.
Place the coated chicken bites on a parchment-lined baking sheet or a wire rack set over a baking sheet. Lightly spray with nonstick cooking spray. Bake in a preheated oven at 400°F (200°C) for about 15-20 minutes, turning halfway through, until cooked through and golden crispy.
While the chicken bakes, combine crushed pineapple (with juice), sugar, brown sugar, lime juice, and soy sauce in a small saucepan. Bring to a simmer over medium heat. Mix cornstarch with a tablespoon of water to make a slurry, then whisk into the sauce. Cook until thickened. Stir in sriracha to taste.
Remove chicken bites from oven and serve warm with pineapple dipping sauce on the side.