Preheat oven to 375F and line an 8x8 baking dish with parchment paper.
In a medium sized bowl, combine oats, pumpkin pie spice, baking powder, and salt. Then add pumpkin puree, dairy free milk, maple syrup, vanilla, and ground flaxseed. Stir well to combine.
Transfer mixture to the prepared baking dish and bake for about 30 minutes, until the top is golden and center is set. Remove from the oven and let cool in the pan for at least 15 minutes before slicing.
Notes
Store in an airtight container in the refrigerator for up to 5 days or in the freezer for up to 3 months. To reheat, bake at 350F for 15-30 minutes or microwave individual portions for 1 minute, or until heated through.