Pumpkin Spice Latte Overnight Oats (Vegan, Gluten-Free)

0 Wet Ingredients: Add the pumpkin puree to a large mixing bowl along with the maple syrup, lemon juice, vanilla, pumpkin pie spice, milk, and espresso. Whisk well, until combined.
1 Dry Ingredients: Add the oats and chia seed or flax seed to the bowl and mix well. Let sit for 10 minutes, to thicken slightly. Add any additional sweetener, spice or lemon juice to taste, if necessary.
2 Serve & Store: Divide between glass jars or airtight containers, adding additional toppings if desired, then store in the refrigerator for up to 5 days.