In a large bowl, whisk together the coconut milk, pudding mix and sweetened condensed milk until smooth and thick. Cover with plastic wrap and refrigerate for 2 hours until set.
In a medium bowl, beat the heavy cream until stiff peaks form. Working in thirds, fold the whipped cream into the pudding mixture until combined.
Place a third of the wafer cookies in the bottom of a trifle bowl and then top with a third of the bananas. Spread a third of the pudding in a layer on top of the banana and top a third of the pineapple. Sprinkle with coconut flakes then repeat until all the ingredients have been used (or your bowl is filled to the top.) finishing with a layer of pudding. Cover and refrigerate for 1 hour or overnight.
Top with crushed wafer cookies, a sprinkle of coconut and garnish with banana or pineapple before serving, if desired.
Notes
Pina Colada Banana Pudding can be made up to 48 hours in advance and stored in the refrigerator covered with plastic wrap.