Forbidden Forrest Butterbeer Chocolate Cake

Name: Forbidden Forrest Butterbeer Chocolate Cake
Prep time: 1 h
Cook time: 30 min
Total time: 1 h 30 min
Cuisine: American
Ingredients: 2 1/4 cups all-purpose flour; 2 1/4 cups granulated sugar; 1 1/2 cups unsweetened cocoa powder; 2 1/4 teaspoons baking soda; 2 1/4 teaspoons baking powder; 1 1/2 teaspoons salt; 3 eggs (at room temperature); 1 cup + 2 tablespoons buttermilk; 1/4 cup + 2 tablespoons plain greek yogurt; 3/4 cup canola oil; 1 1/2 tablespoons vanilla extract; 1 cup cream soda or ginger beer; 1 (11 ounce) bag butterscotch chips; 1/2 cup heavy cream; 2 cups (4 sticks) salted butter (softened to room temperature); 1/2 cup creamy peanut butter; 4 cups powdered sugar; 1 cup unsweetened cocoa powder; 1 tablespoon vanilla extract; 1 (8 ounce) bag marshmallows; 8 ounces melted semi-sweet chocolate chips; 1/3 cup creamy peanut butter; 4 cups crushed pretzel sticks + 1 cup whole pretzel sticks; candy eyes