01 - In a medium bowl or jar, combine the oats, milk, Greek yogurt, brown sugar, cinnamon, and vanilla extract. Stir thoroughly until all ingredients are well incorporated and the brown sugar has dissolved.
02 - Cover the bowl or jar tightly with a lid. Refrigerate for at least 8 hours or overnight to allow the oats to soften and absorb the liquid, creating a creamy, pudding-like texture.
03 - In the morning, remove from refrigeration and stir the oats well. If the mixture appears too thick, add a splash of milk and stir to reach your desired consistency.
04 - Top with sliced banana, chopped nuts, and fresh berries or apple slices if desired. Serve immediately while chilled, or keep refrigerated for up to 3 days.