The Cheesecake Factory - Hershey's Chocolate Bar Cheesecake

Cheesecake Layer:
2 (8-ounce) packages cream cheese, softened
1/2 cup sugar
3 eggs
1/4 cup sour cream
1 tsp vanilla extract
4 oz. chopped Hershey chocolate bar, melted

Chocolate Cake:
2 cups sugar
1-3/4 cups all-purpose flour
3/4 cup HERSHEY'S Cocoa
1-1/2 teaspoons baking powder
1-1/2 teaspoons baking soda
1 teaspoon salt
2 eggs
1 cup milk
1/2 cup vegetable oil
2 teaspoons vanilla extract

Chocolate Frosting:
1/2 cup (1 stick) butter
2/3 cup HERSHEY'S Cocoa
3 cups powdered sugar
1/3 cup milk
1 teaspoon vanilla extract

2 cups Hershey's Milk Chocolate Chips