Preheat the oven to 350°F. Spray a 9" by 13" baking pan with non-stick cooking spray. Place a piece of parchment paper in the bottom of the pan to help prevent sticking.
In a medium bowl, whisk together the rolled oats, flour, sugar, pumpkin pie spice, baking soda, salt, and baking powder.
In a separate bowl, combine pumpkin puree, milk, melted butter, and vanilla extract until well combined and creamy.
Carefully mix the wet mixture into the dry ingredients.
Fold in the dried cranberries and pumpkin seeds.
Pour the batter into the prepared baking pan. Smooth the mixture so it's evenly spread.
Bake for 30 minutes. The mixture will be set and baked through.
Let the mixture cool at least 15 minutes before slicing.
Serve and enjoy. Bars can be frozen for up to 2 months.