Prick the sweet potatoes with a fork and place them into an oven at 180 °C (circulating air). Bake for 45 minutes until soft. Let them cool, peel the skin and purée in a mixer until smooth.
Mix sweet potato mash with cinnamon and 75 ml almond drink and let it rest in the fridge overnight.
Use a second bowl to mix 100 ml almond drink, oats, chia seeds and vanilla. Place in the fridge overnight. In the morning, remove from the fridge and layer both fillings by turns in a glass jar.