Preheat the oven to 400 degrees F. Line a sheet pan with parchment paper.
In a large bowl, whisk 2 tablespoons olive oil, maple syrup, cayenne pepper, 1/2 teaspoon kosher salt and 1/4 teaspoon black pepper. Stir in the squash, coating it in the mixture.
Arrange the squash on the prepared baking sheet in a single layer. Roast for 25-30 minutes, flipping over halfway through roasting until the squash is lightly browned on the edges and tender in the middle.
Place the lentils and 1 teaspoon salt in a medium saucepan and cover with water by 1 inch. Bring to a boil and then reduce to a low simmer with the lid partially on the saucepan. Cook for 15-20 minutes until the lentils are just tender. Taste them to check their doneness after 15 minutes. Once the lentils are ready, pour them into a strainer and rinse with cold water. Transfer the lentils to a large bowl.
For the vinaigrette, whisk the garlic, mustard, 1/2 teaspoon kosher salt, 1/4 teaspoon black pepper, lemon juice, vinegar and 1/4 cup olive oil in a small bowl.
Combine the spinach, red onions, goat cheese, pecans, parsley and squash with the lentils.
Drizzle in the dressing, tossing to coat.