Vanilla Bean Cupcakes with Peanut Butter Buttercream - Cupcake Fanatic

Ingredients

• 1 2/3 cups all-purpose flour
• 1/2 teaspoon baking soda
• 1/4 teaspoon baking powder
• 1/2 teaspoon salt
• 1/2 cup (1 stick) unsalted butter, melted
• 1 cup granulated sugar
• 2 egg whites
• 1/4 cup sour cream (or vanilla yogurt)
• 3/4 cup milk
• 2 1/2 teaspoons vanilla extract
• Seeds scraped from 1/2 a split vanilla bean
• 12-15 peanut butter cups
• 3/4 cups butter, at room temperature
• 1/4 cup shortening
• 1/2 cup creamy peanut butter
• 1 teaspoon vanilla extract
• 1/4 – 1/2 cup heavy whipping cream (or milk)
• 4-5 cups powdered sugar