Lay a peeled banana on a clean cutting board. Choose a banana that is just ripe, meaning fully yellow with no large brown spots. A firmer banana holds its shape better once sliced into rounds.

Spoon the nut butter onto the banana and use a butter knife or small spatula to spread it in a thin, even layer over the entire outside surface. You are not trying to pack on a thick coating, just a smooth, thin layer that the granola can stick to. About 1 1/2 tablespoons of nut butter per banana is the right amount.

Pour the granola onto a shallow plate or small tray and spread it into an even layer. Gently roll the nut-butter-coated banana back and forth through the granola, pressing lightly as you roll so the granola adheres in an even crust. Rotate the banana as you go to coat all sides. If any bare patches remain, press a pinch of granola directly onto those spots with your fingers.

Transfer the coated banana to the cutting board. Use a sharp knife to slice it crosswise into rounds about 1 inch thick. You should get 6 to 8 rounds per banana. The finished pieces look like little sushi rolls, which is exactly the point.

Arrange the rounds cut-side up on a plate. If you like, drizzle a small amount of honey over the top. Serve immediately for the best texture, or add a few drops of lemon juice to the cut surfaces if you need to pack them for later and want to slow browning.