Chocolate cupcakes from billy's bakery in nyc

Ingredients

• 2 sticks unsalted butter (8 ounces)
• 1 cup granulated sugar (7 ounces)
• 1 cup light brown sugar (7-3/4 ounces)
• 4 large eggs (one at a time)
• 6 ounces unsweetened chocolate
• 2 cups cake flour (9-1/4 ounces)
• 1 teaspoon baking soda
• 1 cup buttermilk (room temperature)
• 1 teaspoon pure vanilla extract

Cream:

• 2 sticks unsalted butter (8 ounces)
• 1 cup granulated sugar (7 ounces)
• 1 cup light brown sugar (7-3/4 ounces)

Add:

• 4 large eggs (one at a time)
• 6 ounces unsweetened chocolate (chocolate should be melted, then cooled for approximately 15 minutes before being added).

Add and alternate:

• 2 cups cake flour (9 1/4 ounces)
• 1 teaspoon baking soda

With:

• 1 cup buttermilk (room temperature)
• 1 teaspoon pure vanilla extract

Simple Chocolate Buttercream :

• 4 sticks butter
• 12 ounces semisweet chocolate
• 2 3/4 cups confectioners' sugar
• 1/4 cup whole milk
• 1 teaspoon pure vanilla extract