Preheat the oven to 425 degrees Fahrenheit (220C).
Mix dry ingredients: In a large bowl mix the dry ingredients - flour, oats, sugar, baking powder, baking soda, and salt. Use a whisk to mix everything well.
Mix wet ingredients: In a medium mixing bowl, place the eggs, pumpkin puree, vanilla, oil, and brown sugar. Whisk together until it is well combined.
Fold everything together: Chop the pumpkin seeds with a chopper or a knife until they are little chunks. Add the pumpkin seeds and flour mixture into the wet ingredients. Use a spatula to stir the batter together, about 12-15 folds, just until everything is incorporated. Do not over-stir.
Scoop & bake: Place silicone liners or paper liners into a muffin pan. Add a little less than ⅓ cup of batter to fill each muffin cup. Place the muffin tin in the preheated oven (425 degrees Fahrenheit or 220C) to bake for 7 minutes, then turn the oven down to 375 degrees Fahrenheit (190C) and bake for another 7-8 minutes. Remove muffins from the oven when they spring back from the touch and when the center does not look gooey.