Prep the fruit. Core and chop the apple.
Leave the peel on for fiber and color. If your banana isn’t frozen, add a few extra ice cubes later.
Load the blender. Add milk first, then yogurt, apple, frozen banana, rolled oats, maple syrup, cinnamon, nutmeg, vanilla, and a small pinch of salt.
Blend until smooth. Start on low to break down the oats and apple, then increase to high for 30–45 seconds. Scrape down the sides if needed.
Adjust thickness. For a thicker smoothie, add a few ice cubes or an extra tablespoon of oats and blend again.
For a thinner drink, splash in more milk.
Taste and sweeten. If you want it sweeter, add another teaspoon of maple syrup or a soft Medjool date, then blend briefly.
Serve immediately. Pour into a chilled glass. Top with a sprinkle of cinnamon or a few granola crumbles for a pie-like crunch.