Preheat oven to 350 degrees F and grease a 9x13" metal baking pan.
In a large mixing bowl, whisk mochiko, sugar, baking powder, pumpkin pie spice, cinnamon, and salt.
In a separate bowl, beat eggs with pumpkin puree, condensed milk, evaporated milk, melted butter, and vanilla.
Combine wet and dry ingredients and mix well until fully incorporated.
Bake for one hour or until a toothpick poked in the center comes out clean.
Let rest for at least one hour before slicing.
Leftovers can be kept in an airtight container in the refrigerator.
