In a large sauté pan, melt the butter over medium heat. Stir in the maple syrup, salt, cayenne, and 1/4 cup water. Add the carrots. Bring to a boil. Reduce heat and simmer until the carrots are just tender and the glaze has thickened, 15 to 20 minutes, tossing gently every few minutes. Sprinkle with the pepper.