To make salad: Heat grill to medium-high heat. In small bowl, whisk 1/4 cup olive oil, white wine vinegar, Dijon mustard, garlic powder, salt and pepper, to taste. Set aside. Brush cut sides of peach halves with remaining olive oil and grill until grill lines appear and peaches become tender, 3-5 minutes. Remove peaches and cut into slices. Divide greens among four plates. Top with grilled peach slices and goat cheese. Divide 1 cup spiced pecans evenly among salads and reserve remaining cup for snacking. Drizzle each salad with vinaigrette.