Black Widow Peanut Butter Bars

Bahan-bahan (24 porsi)

• 1 1/2 sticks (3/4 cup) salted butter
• 2 cups creamy peanut butter
• 3/4 cup light brown sugar
• 1/4 cup granulated sugar
• 2 large eggs, at room temperature
• 1 tablespoon vanilla extract
• 2 cups all-purpose flour
• 1 teaspoon baking powder
• 1/2 teaspoon kosher salt
• 1 stick (1/2 cup) salted butter, at room temperature
• 2 -3 cups powdered sugar
• 1/2 cup cocoa powder
• 2 teaspoons vanilla extract
• 1/4 cup warmed milk
• marshmallows
• whoopers
• candy eyes
• melted chocolate
• black or silver sprinkles
• small plastic spiders (optional)