Sweet Potato Cream Cheese Brownie Pie

Name: Sweet Potato Cream Cheese Brownie Pie
Ingredients: 4 tablespoons butter; 2 ounces bittersweet chocolate, chopped; 1/4 cup sugar; 1 egg; 1/4 cup all-purpose flour; 1/2 teaspoon baking soda; Dash salt; 1/4 cup chopped walnuts; 2 (8-ounce) packages cream cheese, softened; 3/4 cup sugar; 1/4 cup sour cream; 2 tablespoons heavy cream; 1 tablespoon all-purpose flour; 1/2 teaspoon maple flavoring; 4 egg whites; 1 1/2 cups powdered sugar; 1/2 teaspoon ground cinnamon; 1/4 teaspoon ground nutmeg; 3/4 cup cooked sweet potato; 1 (14-ounce) package individually wrapped caramels; 1 can evaporated milk; Chocolate Ganache:; 1 cup heavy cream; 1 pound semisweet chocolate chips; Chopped pecans, for garnish