Grease a dinner dish with unsalted butter and set aside. Place about 1 cup of granulated sugar on another plate and set aside.
Mix the condensed milk, pumpkin puree, butter, and apple pie spice in a medium saucepan over medium heat.
Cook, stirring constantly in order to avoid burning, until thickened enough that the bottom of the pan shows through briefly when the mixture is stirred, and runs to the sides of the pan slowly.
This should usually take approximately 10-12 minutes (large burner) or 15-20 minutes (small burner).
Remove from heat, stir in the vanilla, and pour mixture into the greased dish. Let cool. The brigadeiro dough can be refrigerated for about 20 minutes before rolling into balls if desired.
Then grease hands well with butter and shape the brigadeiros into balls, using a tablespoon as measure.
Roll pumpkin brigadeiros in sugar, flatten a bit both the top and botton of the brigadeiros and shape the sides with a toothpick, making vertical marks.
Place them into bonbon cups, and top with a clove. Use both colors of icing to decorate them as pumpkins.