Preheat your oven to 350°F (175°C) and line your muffin tin with liners or grease it lightly.
In a large bowl, combine rolled oats, baking powder, cinnamon, and salt. Mix well to ensure even distribution.
In another bowl, whisk together the pumpkin purée, eggs, and honey or maple syrup until fully combined.
Pour the wet mixture into the dry ingredients and mix gently until just combined.
Use a scoop to fill each muffin liner about 2/3 full. Optionally, top each muffin with a sprinkle of oats or nuts.
Bake in the preheated oven for 20-25 minutes or until a toothpick inserted into the center comes out clean.
Let muffins cool in the tin for 5-10 minutes before transferring them to a wire rack.