Good-Cooking - Philadelphia Chocolate Royale Cheesecake

Ingredients

• 4 (8 ounce) packages PHILADELPHIA Cream Cheese, softened
• 1 cup granulated sugar
• 1 teaspoon vanilla extract
• 1 package (8 squares) BAKER'S Semi Sweet Baking Chocolate, melted, slightly cooled
• 1/4 cup hazelnut liqueur (optional)
• 4 eggs
• 18 OREO Chocolate Sandwich Cookies, finely crushed
• 2 tablespoons butter or margarine, melted