Mattie: I can tell you used to own a bakery. You're so perfect. I, on the other hand am incredibly lazy. I roast my small, sweet pumpkins in one of two ways. Cut off the top as you suggested and put one or two in a crockpot with a couple of inches of water and walk away for a few hours. Remove, cut in half, scoop out the innerds, then scoop the meat from the shell. This is a bit messy and the pumpkin is moist and not caramelized.
A better way is to take a baking dish, line with parchment paper and two inches of water. Remove, or not, I don't the stem. Lightly grease with coconut oil, punch a couple of holes in the top third with a knife and bake at 350 until soft. It takes longer but it's sooo much easier. They scoop out easier than the crock pot method, the flesh is firmer and has a better flavor.
You can do this at night when doing other things and refrigerate until you're ready for them. Besides I don't trust myself with a sharp knife!