Preheat oven to 375°F (190°C). Line a 12-cup muffin tin with liners or lightly grease it.
Soften oats: In a large bowl, whisk together the milk and pumpkin puree. Stir in the oats and let sit for 10–15 minutes so they soften.
Add wet ingredients: Once oats are softened, whisk in the melted butter, splash of olive oil, eggs, maple syrup, and vanilla until well combined.
Mix dry ingredients: In a small bowl, whisk together the flour, baking powder, baking soda, salt, and pumpkin pie spice.
Combine: Add the dry ingredients to the wet mixture. Gently stir until just combined—don’t overmix.
Bake: Divide the batter evenly among the muffin cups. Bake for 18–20 minutes, or until a toothpick inserted into the center comes out clean. Cool: Let the muffins cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.
