Skinny Scalloped Potato Gratin

Name: Skinny Scalloped Potato Gratin
Ingredients: olive oil spray (I used my misto); 6 medium peeled yukon gold potatoes, sliced 1/8-inch-thick (2 lb 4 oz peeled); 2 tbsp light butter, melted; salt and fresh pepper to taste; 1/2 tsp garlic powder; 3 oz (3/4 cup) shredded reduced fat Cheddar (I used Cabot); 1 cup fat free milk; 1 bay leaf; pinch freshly grated nutmeg; 2 tsp thyme