Step 1
Place the butternut squash and dates into a 6- to 8-quart slow cooker. Season generously with kosher salt and black pepper. In a separate bowl, mix together the cinnamon stick, sweet paprika, turmeric, cumin, hot smoked paprika, ground ginger, cloves, and cayenne pepper, and set aside.
Step 2
Heat the canola oil in a large skillet over medium-high heat. Pat the chicken thighs dry and season with salt. Cook the chicken in batches, placing the skin-side down in the skillet. Allow the skin to brown deeply and become crisp, which should take about 5 to 8 minutes per batch. Once browned, transfer the chicken to the slow cooker, arranging it skin-side up in a single layer on top of the squash.
Step 3
Lower the heat on the stovetop to medium. If there is excess fat in the skillet, discard all but a thin layer. Add the chopped onion to the skillet and season with salt. Sauté the onion until softened, about 5 minutes, making sure to scrape up any browned bits from the pan. Add the minced ginger and garlic, cooking until fragrant, about 1 minute. Stir in the reserved spice mixture, cooking for an additional 30 seconds until well combined. Add the lemon juice and stir to incorporate the browned bits from the pan. Pour the mixture over the chicken in the slow cooker.
Step 4
Set the slow cooker to cook on low for at least 4 hours and up to 6 hours, or until the chicken and squash are very tender and the flavors have fully melded. After 6 hours, the slow cooker can be switched to the "warm" setting, and the dish can remain in this mode for up to 2 more hours without the chicken drying out. Before serving, discard the cinnamon stick and adjust the seasoning with more lemon juice and salt as desired. Fold in the chopped parsley and sliced scallions. Serve with couscous or pita, and top with yogurt and toasted almonds, if desired.