Make the pineapple dip: combine the crushed pineapple, 1/4 cup sugar, 3 tablespoons lime juice and 2 teaspoons cornstarch in a blender; blend until very smooth.
Transfer the blended pineapple to a small saucepan and simmer over medium-low heat about 5 minutes, stirring, until slightly thickened; remove and refrigerate while you prepare the chicken.
Preheat the oven to 400°F (204°C). Line a baking sheet with foil and lightly spray with nonstick cooking spray.
Toast the coating: pulse the coconut flakes in a food processor to break them into smaller pieces. In a large nonstick skillet, melt 2 tablespoons butter with 1 tablespoon coconut or olive oil over medium heat, add the coconut and panko, and toast until golden, stirring often; transfer to a large bowl.
Process the cashews in the food processor until they are about the size of panko crumbs, then stir them into the coconut-panko mixture. Add 1/2 cup flour and the breading spices (salt, 1/2 teaspoon brown sugar, garlic powder, ground ginger, black pepper, onion powder, chili powder, and cayenne) and mix to combine.
Make the batter: whisk the whole egg and egg yolk in a large bowl. Add 1/2 cup flour, 1 tablespoon soy sauce, 1 tablespoon brown sugar, and 2 teaspoons lime juice; whisk until smooth.
Add the chicken pieces to the batter and toss until each piece is evenly coated; let excess batter drip off before breading.
Working in batches, transfer battered chicken pieces to the coconut-cashew mixture and press the coating onto each piece so it adheres; place coated pieces on the prepared baking sheet.
Lightly spray the coated chicken with nonstick cooking spray. Bake at 400°F for about 10 minutes or until chicken is cooked through (internal temperature 165°F), then broil 2–3 minutes until golden and crisp.
Serve the baked coconut cashew chicken bites with the chilled pineapple-lime dipping sauce.
