Preheat the oven to 450 degrees ;. On a baking sheet, toss the squash with 1 tablespoon olive oil and season with salt and black pepper. Spread out in a single layer and roast until tender and just starting to brown, about 10 minutes; let cool.
Meanwhile, in a large skillet, fry the bacon, stirring, until crisp, about 15 minutes. Using a slotted spoon, transfer to paper towels to drain; let cool.
In a small bowl, whisk together the remaining 1/4 cup olive oil, the maple syrup, lemon juice and a pinch of cayenne. Drizzle the dressing over the spinach; toss to coat.
In a serving bowl, top the spinach with the bacon on one side of the bowl and the squash on the other side.