Drain pineapple, reserving juice in a 1 cup measure; set pineapple aside. To the juice, add enough water to measure 1 cup. Transfer to a small saucepan; add the unflavored gelatin and let stand for 1 minute. Bring to a boil. Add cherry gelatin; stir until dissolved. Stir in ginger ale. Pour into a bowl. Refrigerate for 30 minutes or until partially set.
Whisk in the pineapple and cranberry sauce. Transfer to an 11x7-in. dish coated with cooking spray. Refrigerate until set.
In a large bowl, beat cream cheese until smooth. In a small bowl, beat whipped topping mix, milk and vanilla on low speed until blended. Beat on high for 4 minutes or until thickened. Add to cream cheese; beat until blended. Spread over gelatin. Refrigerate overnight. Cut into squares; garnish each with a pecan half and cranberry.