Candy Cane Sheet Cake

Name: Candy Cane Sheet Cake
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Cuisine: American
Ingredients: 1 tablespoon vanilla (5mL); ¼ teaspoon salt (1g); ⅔ cup crushed candy cane (⅓ with the batter, ⅓ sprinkled on top and swirled); 1 ¼ cups whole milk (300mL); 1 1/2 cups granulated sugar (300g); 3/4 cup unsalted butter (255g, room temp); 1/2 cup sour cream; 6 egg whites; 2 1/2 cups all purpose flour; 4 tsp baking powder; 3 sticks unsalted butter (340g, room tem); 1 lb confectioners sugar (sifted); 1 teaspoon vanilla (5mL); ½ teaspoon peppermint extract (2mL); ¼ cup milk (60mL)