Preheat oven to 425° with a rimmed baking sheet on the middle rack. Fill a large pot with water and bring to a rolling boil over high heat.
While water is heating, score the chestnuts. Carefully cut an X on the flat side with a paring knife, cutting just through the shell but not into the meat inside.
Blanch the scored chestnuts in boiling water for 60 seconds, then drain. Arrange chestnuts cut-side-up on the preheated baking sheet.
Roast at 425° for 25-30 minutes, until shells begin to curl back.
While chestnuts are roasting, brown butter in a small saucepan. Remove from heat and whisk in vanilla, spices, and salt.
When chestnuts are done, cover loosely with a kitchen towel and let cool until you can handle them. Peel the shells & skins of the chestnuts while they're still warm for easier removal.
Toss the shelled chestnuts in the spiced butter and serve warm.