Prepare the cake per the instructions on the box in a 13 x 9 inch pan. Immediately after removing from the oven use the handle of a wooden spoon or similar to poke holes all over the cake.
In a medium mixing bowl, whip together both boxes of cheesecake pudding mix with 3 cups of cold milk. Whip until thickened but still pourable. Spread over the cake and into the holes. Chill completely.
To frost, use a hand mixer to cream together 2  oz softened cream cheese, powdered sugar and vanilla. Add the whipped topping or fresh whipped cream and beat until fluffy.
Spread over the cooled cake and garnish with toasted pecans. Store chilled.