S'mores Cupcakes - The Merrythought

Ingredients

• 1½ cups graham cracker crumbs
• ¼ cup sugar
• 5 1/3 tbsp. unsalted butter, melted
• 1 3/4 cups cake flour
• 1 1/4 cups unbleached all-purpose flour
• 2 cups sugar
• 1 tablespoon baking powder
• 3/4 teaspoon salt
• 1 cup (2 sticks) unsalted butter, cut into 1-inch cubes
• 4 large eggs
• 1 cup whole milk
• 1 teaspoon pure vanilla extract
• 6 oz. semi-sweet chocolate, finely chopped
• ¾ cup plus 1 ½ tbsp. heavy cream
• 3 tbsp. unsalted butter, cut into 3 pieces, at room temperature
• 6 large egg whites, at room temperature
• 1 ½ cups sugar
• 1/2 tsp. cream of tartar
• 1 ½ tsp. vanilla extract