Kue Jack-O'-Lantern Coklat Isi Selai Kacang

Bahan-bahan (12 porsi)

• 1 stick (8 tablespoons) salted butter, at room temperature
• 3/4 cup granulated sugar
• 1 teaspoon pure vanilla extract
• 1 egg, at room temperature
• 1 1/4 cups all-purpose flour
• 1/2 cup + 2 tablespoons dark chocolate cocoa powder
• 1/4 teaspoon baking soda
• 1/2 teaspoon kosher salt
• 12 ounces milk chocolate, melted
• 3/4 cup creamy peanut butter
• 4 tablespoons salted butter, at room temperature
• 1/4 cup powdered sugar
• 1 teaspoon vanilla extract
• 1/4 teaspoon kosher salt
• flaky sea salt