Caramel frappuccino cupcakes

Ingredients

• 1/2 cup of hot coffee
• 1/2 cup of cocoa powder
• 1/2 cup of cold water
• 1 1/2 cups of cake flour
• 1 teaspoons of baking soda
• 1/4 teaspoon of baking powder
• 1/4 teaspoon of salt
• 1 stick of unsalted butter
• 1 1/4 cup of sugar
• 2 large eggs
• 3/4 teaspoon of pure vanilla extract

Marshmallow Frosting:

• 4 large egg whites, at room temperature
• 1 cups sugar
• 1/4 tsablepsoon cream of tartar
• 1 tablespoon vanilla extract

Easy Caramel Sauce :

• 1/2 cup heavy cream
• 3 tablespoons butter
• 3 tablespoons lightly corn syrup
• 1 1/2 cup packed light brown sugar