01 - Preheat oven to 375°F (190°C).
02 - Place the diced butternut squash on a baking sheet. Drizzle with 1 tablespoon olive oil, sprinkle with salt and pepper, and roast for 20-25 minutes until tender. Let cool slightly.
03 - In a skillet, heat remaining olive oil over medium heat. Sauté the onion until translucent (about 4 minutes), then add garlic and cook 1 minute more. Stir in baby spinach and cook until wilted. Remove from heat.
04 - In a large bowl, whisk together eggs, milk or cream, cumin, paprika, nutmeg, thyme, black pepper, and salt.
05 - Add the pumpkin puree, roasted butternut squash, sautéed vegetable mixture, cheese, and fresh sage (if using). Mix until well combined.
06 - Roll out the pie crust and fit into a 9-inch pie pan. Trim and flute edges as desired.
07 - Pour the filling into the prepared crust and smooth the top. Bake for 35-40 minutes, or until the center is set and the top is golden brown.
08 - Allow the pie to cool for at least 10 minutes before slicing. Serve warm or at room temperature.