Step 1: Preheat the oven at 400F and roll out the puff pastry. Line a baking sheet with parchment paper. With a cookie cutter cut 2 inch disks from the puff pastry and place them on the parchment paper. Cover the disks with more parchment paper and place another baking sheet on top to avoid over puffing while the pastry cooks.
Step 2: Place the baking sheets in the oven and cook for approximately 15 minutes, then remove the top baking sheet and cook for additional 5 minutes until the disks are golden brown.
Step 3: Place the heavy whipping cream in a medium saucepan and bring to a boil. After the cream reaches the boiling point, turn off the heat and pour in the chopped chocolate. Wait a couple of minutes and add 2tbsp of rum, then stir the mixture until it is well combined. Transfer the ganache in a heat proof bowl and place in an ice bath to cool completely.
Step 4: Place the remaining rum, the sugar and frozen cherries in a pan over medium heat. Stir until the sugar is dissolved then bring to a boil to caramelize the cherries. When the cherries are completely cooked transfer to a bowl and let cool (using an ice bath if necessary)
Step 5: Whip the ganache with a hand held mixer until it is fluffy and the color turns lighter brown.
Step 6: To assemble the napoleon place a disk of cooked puff pastry on the serving dish. Scoop some ganache with a medium ice cream scoop or a pastry bag. Insert a cherry in the middle of the cream and cover with another puff pastry disk, then repeat until the napoleon has 3 floors.