Combine rolled oats, unsweetened almond milk, and vanilla Greek yogurt in a clean jar or airtight container. Add chia seeds, maple syrup, and vanilla extract, and mash in a ripe banana until blended.

Stir the mixture vigorously with a spoon or small whisk until even; ensure there are no dry clumps.

Seal the container and refrigerate for at least 4-6 hours or overnight.

In the morning, remove the container and stir well. If too thick, add a splash of almond milk to reach desired consistency.

Add graham cracker crumbles and additional banana slices on top before serving.

Serve directly from the jar or in a bowl, and enjoy!