In a medium mixing bowl, mix the maple syrup, vanilla, yogurt, pumpkin and oat milk with a whisk until fully combined and smooth with no lumps of pumpkin.
Add the oats, chia seeds, salt and pumpkin pie spice and mix well until fully combined.
Cover with plastic wrap or transfer to a storage container and place in the fridge for at least 6 hours up to overnight.
To layer the overnight oats in a mason jar, spoon 1 tbsp yogurt of choice into the bottom of a jar, scooping some of the oats overtop, filling the jar about half way. Repeat with more yogurt and another layer of oats. Top with your choice of garnishes such as yogurt or dairy-free whipped cream, pecans or pumpkin pie spice.
If you're not layering with yogurt, simply scoop the overnight oats into a bowl, add your toppings and enjoy!