Sweet Potato Casserole

Adjust rack to middle position and heat oven to 375 degrees. In large pot of boiling water, parboil sweet potato slices until they are bright orange, 4-5 minutes. Drain well and turn into a buttered 13 x 9 inch baking dish. Whisk melted butter, honey, molasses, ginger, salt and cayenne in a small bowl. Set aside. Mix cornstarch with 2 tablespoons cold water until smooth, then whisk into butter mixture. Pour over sweet potatoes and toss to coat well. Cover tightly with foil and bake until bubbly, about 50 minutes. Remove foil, stir gently and bake until liquid thickens to glaze potatoes, about 20 minutes more. Cool slightly and serve.