Preheat oven to 350 degrees F.
Prepare yellow cake mix as directed using a greased 13 by 9 by 2-inch pan and bake for 30 to 35 minutes. While cake is baking, combine the pineapple and 1 cup of sugar in a saucepan, and bring to a boil over medium heat stirring constantly. Remove from heat and allow to cool slightly.
Remove cake from oven and using a fork, pierce holes into cake. Pour pineapple mixture over hot cake and set aside.
Prepare pudding according to package directions. Spread pudding over cake and refrigerate until thoroughly chilled. Whip heavy cream and remaining sugar until stiff. Cover top of cake with whipped cream and sprinkle toasted coconut on top.