Combine the dry ingredients: Rolled oats, cocoa powder, and chia seeds in a mixing bowl and whisk together.

Add the wet ingredients: Pour in almond milk, sweetener, and vanilla extract. Stir until well combined.

Transfer the mixture into a clean mason jar, leaving space for expansion.

Seal the jar and refrigerate for at least 4 hours or overnight.

In the morning, stir well and add optional toppings before serving.