Preheat the oven to 350 degrees and boil a few cups of water in a small pot on the stove.
Remove the seeds from a medium-sized sugar pumpkin and rinse off any excess pumpkin bits. (Don’t throw away the pumpkin! Here’s a tutorial about how to roast the pumpkin to make pumpkin puree.)
In the small pot, simmer the seeds in gently boiling water for 10 minutes.
Drain the seeds and pat them dry with a clean cloth.
Stir the syrup and vanilla together in a small bowl. Pour over the seeds and stir to coat.
In another small bowl, mix together the spices. Pour them over the pumpkin seeds and stir.
Place the seeds in a single layer in a roasting pan. Bake for 15-20 minutes, stirring every five minutes. They’re done when they’re nice and crispy, but not too brown.
Remove the seeds from the oven and let them cool. Store them in an airtight container.
If you don’t eat the seeds within a few hours, they may become chewy instead of crunchy. Just put them under the broiler for a minute or two to get them crispy again.