Preheat oven to 350 degrees Fahrenheit. Line a 12 cup muffin tin with silicone baking cups or lightly oil with melted coconut oil.

Combine almond milk, apple cider vinegar, maple syrup, and pumpkin puree in a large mixing bowl.

Add baking powder, baking soda, cinnamon, nutmeg, and salt. Stir until fully combined.

Add oat flour and oats to the mixture and stir until combined. Add walnuts or nuts of choice and stir.

Scoop mixture into the prepared baking tin. Evenly distribute batter between the 12 cups.

Bake at 350 degrees for 30 minutes, or until a toothpick comes out clean.