Swirled Caramel Sheet Cake with Fudgy Chocolate Frosting

Name: Swirled Caramel Sheet Cake with Fudgy Chocolate Frosting
Prep time: 30 min
Cook time: 35 min
Total time: 1 h 5 min
Cuisine: American
Ingredients: 2 sticks (1 cup) salted butter, at room temperature; 1 1/4 cups granulated sugar; 1 tablespoon vanilla extract; 3 large eggs, at room temperature; 2 1/2 cups all purpose flour; 1 1/2 teaspoons baking powder; 1/4 teaspoon baking soda; 1/2 teaspoon kosher salt; 1 1/3 cups milk, at room temperature; 1 1/2 sticks (3/4 cup) salted butter, at room temperature; 1/2 cup dark brown sugar; 1/2 cup maple syrup; sea salt; 2 cups semi-sweet chocolate chips; 1 1/3 cups sour cream; 1 teaspoon espresso powder ((optional))