Rocky Ledge Bars

Ingredients (12)

• 1/2 cup 1 stick unsalted butter, room temperature, plus more for pan
• 2 1/4 cups all-purpose flour
• 2 1/4 teaspoons baking powder
• 1 teaspoon coarse salt
• 1 1/2 cups packed dark-brown sugar
• 3 large eggs
• 1 teaspoon pure vanilla extract
• 1 cup miniature marshmallows
• 1 cup semisweet chocolate
• 1 cup white chocolate
• 1 cup butterscotch chips
• 18 soft caramel-candy cubes