Preheat the oven to 350 degrees. Grease a 13 by 9 inch baking dish.
In the center of a large mixing bowl, whisk together the dry ingredients: sugar, flour, baking powder, and cinnamon. Into a well in the center of the dry ingredients, add and whisk the eggs. Whisk until fully mixed.
Whisk and mix in the other wet ingredients: pawpaw puree, milk, and butter. Pour and scrape the batter into the baking dish and bake 50 minutes. To test for doneness, slide a toothpick into the center of the pudding, and it should come out clean. Like custard, if you jiggle the pan, the center should be set.
Serving: Cut the pudding into squares, and serve it with vanilla ice cream, whipped cream, hard sauce, or crème anglaise.