Preheat the oven: Set oven to 350°F (175°C). Line or grease 2 muffin cups per serving.
Prepare the muffin base: In a mixing bowl, combine crushed pineapple, shredded coconut, and mashed banana.
Add wet ingredients: Stir in vegetable oil, egg, and vanilla extract until well blended.
Mix in dry ingredients: Add sugar, cinnamon, salt, and baking soda. Stir to combine.
Add flour and nuts: Gently fold in the flour, then stir in chopped macadamia nuts. Do not overmix.
Fill muffin tin: Divide batter evenly into the prepared muffin cups. Top with additional chopped nuts, if desired.
Bake the muffins: Bake for 20–22 minutes, or until a toothpick inserted in the center comes out clean. Let cool for 5 minutes in the pan, then transfer to a wire rack.
Make the smoothie: In a blender, combine strawberries, oat milk, maple syrup, vanilla extract, and ice if using. Blend until smooth and creamy, about 45–60 seconds. Adjust sweetness and consistency as needed.
Serve the muffins with fruit and smoothie.