Preheat oven to 180 degrees C. Lightly grease a 20x30cm baking dish.
Sift together the mochiko, baking powder and sugar in a large bowl. Mix together the eggs, pumpkin puree, condensed milk, butter and vanilla essence in a separate bowl. Stir the egg mixture into the mochiko mixture. Pour into the prepared dish.
Bake in preheated oven for 1 hour. Allow to cool before serving.