Preheat oven to 275 degrees. Put hazelnuts on parchment lined baking sheet. Bake for 30 minutes. Remove and cool. Remove skin, put in plastic bag and crush using a rolling pin.
Preheat oven to 400 degrees. Line baking sheet with parchment and drizzle 1T olive oil on top. Arrange squash, parsnip and apple in dish. Top with thyme and pour 1/4 cup water over top. Bake uncovered for 45 minutes.
Remove dish from oven. Discard thyme and allow squash to cool.
Heat 1T olive oil in pan over medium low heat. Add onion and salt. Saute 10 minutes. Do not brown.
Take peel off squash and puree. Puree parsnips, apples, and onion separately. Add broth to puree.
Put squash puree and parsnip puree in large stock pot. Add remaining broth. Bring soup to boil then reduce to simmer.
While soup is simmering add cumin, allspice, salt, and white pepper. Before serving stir in a half cup of heavy cream.
Serve in bowls and top with crushed roasted hazelnuts and scallions.