Preheat the oven to 425°F. Line a large rimmed baking sheet with parchment paper. Pat the yellowtail snapper very dry with paper towels. Using a sharp knife, make 3 or 4 diagonal cuts through the skin on each side of the fish, cutting almost to the bone.

Place the fish on the prepared baking sheet. Brush both sides and the inside cavity with the avocado oil. Season lightly with salt and pepper.

In a small bowl, whisk together the white miso, maple syrup, rice vinegar, sesame oil, garlic, and ginger until smooth.

Spread about two-thirds of the miso mixture over the flesh side of the fish, working some into the cuts. Reserve the remaining marinade. Let the fish stand at room temperature for 15 minutes.

Roast the fish, flesh-side up, for 12 to 14 minutes, depending on the thickness of the fish. The flesh should be nearly cooked through and flake easily when tested near the thickest part.

While the fish roasts, place the Matcha Koji Granola in a small food processor. Pulse 3 to 5 times, just until coarsely crushed. You want a mixture of small crumbs and little crunchy pieces, not a powder. Transfer to a small bowl and stir in the sesame seeds, 1 teaspoon avocado oil, and lime zest.

Remove the fish from the oven. Brush the remaining miso marinade over the flesh. Generously sprinkle the granola mixture over the top, gently pressing it into the marinade so it adheres.

Return the fish to the oven and roast for 3 to 4 minutes, until the granola is lightly toasted and the fish is completely cooked. If you want a little extra color on the topping, broil for 30 to 60 seconds, watching carefully so the granola doesn't burn.

Carefully transfer the snapper to a long serving platter. Scatter the thinly sliced green onions and cilantro over the granola crust.

Cut one lime into wedges and arrange them around the fish. Squeeze the juice of the remaining lime over the fish just before serving.