Preheat oven to 350°F. Toss pecans, canola oil and pumpkin pie spice together and place in a single layer on a rimmed baking sheet. Bake for 10 minutes, shaking pan once during baking time. Let cool.
Warm a large skillet over high heat, mist lightly with cooking spray and cook corn for about 3 minutes, until corn turns slightly brown. Let cool.
Make vinaigrette: Whisk mustard, vinegar, shallot and garlic together. Add oil in a slow stream, whisking constantly. Season with salt and pepper to taste.
Toss all salad ingredients together. Add vinaigrette, toss well and serve.