Chocolate S’mores Cupcakes

Name: Chocolate S’mores Cupcakes
Cook time: 1 h
Total time: 1 h
Cuisine: American
Ingredients: 1 tsp. vanilla extract; 1 cup miniature marshmallows; 1/4 tsp. salt; 1/2 tsp. cream of tartar; 1 tbsp. light corn syrup; 6 tbsp. water; 1 cup sugar; 2 egg whites; 3/4 cup boiling water; 2 tsp. vanilla extract (best quality available); 1/2 cup vegetable oil; 1 cup whole milk; 3 eggs; 1 tsp. salt; 1 1/2 tsp. baking soda; 1 1/2 tsp. baking powder; 3/4 cup unsweetened cocoa (best quality available); 1 3/4 cups all purpose flour; 2 cups sugar