In a small microwave safe dish, add the chopped plums and water. Cook in 30 second increments until the plums are soft and start to break down into a sauce consistency. It should also start to thicken, I usually cook mine for about 2 minutes total.
Stir in the ground cinnamon, ground ginger, 1/4 tbsp maple syrup and vanilla extract. Set aside to cool.
In a small jar or container, that's at least 250mL, add your oats and chia seeds. Stir to combine. Then add in the oat milk, yogurt and 1/2 tbsp of maple syrup. Stir to combine.
Spoon the plum sauce on top of the oat mixture. (**see notes) Seal the container and chill in the fridge for at least 6 hours and enjoy!
Notes
*You can peel the plum if you like but I don't. I barely ever peel fruit when I'm baking. It's more nutritious to eat the skin plus there's less waste.**If you prefer, you can just stir the plum sauce in. You can also put sauce on the bottom of the jar and on top of the oats but you'll need to dirty up more dishes this way. My favourite way is layering the sauce on top of the oats.