In a mixing bowl, combine rolled oats, cocoa powder, and chia seeds if using. Pour in your choice of milk, stirring everything together thoroughly.

Drizzle in maple syrup or honey along with the vanilla extract, mixing until they are fully incorporated.

Fold half of the chopped fresh strawberries into the oat mixture, reserving the rest for topping later.

Transfer the oat mixture into jars or individual bowls, layering on the remaining strawberries on top.

Cover the jars or bowls and refrigerate the oats overnight, or for at least four hours.

In the morning, enjoy the oats directly from the jar or transfer them to a bowl.