Drain the syrup out of the canned cherries and place them in a bowl. Cover the cherries with the rum and let them soak for 24 hours in the fridge.
Preheat the oven to 350°F. Beat the eggs with sugar until they double in volume. In a separate bowl, combine the flour and cocoa together.
In thirds, fold the flour mixture into the egg mixture, being extra careful not to over mix the dough.
Spread the dough onto a baking sheet lined with parchment paper (10" X 15" is the perfect size). Bake for 12 minutes.
Remove the cake from the oven and place a kitchen towel over the cake. Roll up the shorter side. Let the roll cool to room temperature and remove the towel and parchment paper.
Filling & Topping
Drain the rum from the cherries and dice the cherries into small pieces. Set them aside.
Unroll the cake and spread the cherries over it. Let the cherry mixture soak into the cake for a few minutes while you whip up the cake cream.
Whip the condensed milk with the cacao and extra cold heavy whipping cream.
Spread a thick layer of cream over the cherries. Roll the cake back up and cover the outside with the remaining cake cream. Decorate the top with cherries, chocolate shavings, and/or cacao.
Let the cake rest overnight before serving. Enjoy!