To make the bowls: Preheat the oven to 400 F and line a large baking sheet with parchment paper.
Using a paring knife, cut a large circle around the stem of each acorn squash. Remove the lid and scoop out the seeds and fibers. pepper Place the squash and lids on the prepared baking sheet along with the onions. Drizzle with 1/4 cup of olive oil and season with salt and pepper. Cut top of garlic bulb to expose cloves, drizzle with remaining one tablespoon. of oil, wrap in foil and place on baking sheet with squash and onion.
Bake for 45-50 minutes until squash, onion and garlic have softened.
Scoop out squash and place in a food processor, ensuring you leave a layer in squash to hold soup. Add onion, roasted garlic without the skin and apple. Add vegetable stock and puree until creamy.
Pour soup in large pot over medium heat and add all the spices. Cook until hot and bubbly.
Serve in warm soup bowls or in roasted whole acorn squash . Top with thick Greek Yogurt, croutons and cilantro if using.