Peel and cut the potatoes into medium sized cubes, and boil until fork tender. Once the potatoes have cooked, mash them, combine with the coconut, vanilla, evaporated milk, water, sugar, salt, and ricotta, and mix well until all ingredients have combined.
Set the mashed potato mixture on low heat, stirring constantly, and let the mixture cook for 30 minutes. Add the butter and condensed milk and cook for another 10 minutes.
To assemble the custards, using a 4-inch round cookie cutter, cut 12 cake pieces from the cake layers. Using a round 4-inch mold or can, place one layer of cake at the bottom. Add approximately 2 tablespoons of the custard on top, repeat with another layer of cake, custard, and finish with a top layer of the cake. Repeat this process for each individual custard until all of the cake layers are used, and you have enough for your guests. Refrigerate for 1 hour.
In a small saucepan, combine the strawberries, water, and sugar, cook over medium heat until sugar is melted and strawberries are cooked, approximately 15 minutes. Using a blender, blend strawberry mixture until smooth. Set aside.
Once the custard cakes have been assembled and refrigerated, roll each custard in confectioners' sugar, and dust the tops with the cocoa powder.
To serve, place each custard on a plate, drizzle the strawberry sauce around the dessert, and add a dollop of whipped cream to each dessert. Garnish with lime zest.