Preheat oven to 355 F/180 C. To make the shortbread cookie crust, place shortbread fingers in the bowl of a food processor and crush until bread crumbs. Add melted butter and mix with a rubber spatula or your hands. Transfer the mixture into a rectangular tart pan with removable bottom. Using your hands, pat out cookie crumbs, so they cover the bottom and sides of the pan to meet the edge. Then bake for 10 minutes. Remove the cookie crust from the oven and bring it to the freezer right away for 30 to 60 minutes.

Keep the oven temperature at 355/180 C. To make caramelized apples, place granulated sugar in a saucepan and bring over medium heat. Swirl the pan with sugar over your stove to get the caramel. Pour caramel onto parchment paper and let it cool down. Brake the caramel into pieces and reduce it to powder, using a chopper or a food processor. Peel apples and cut them into big cubes and place them in a dish. Add the lime zest, the caramel powder, and mix. Cover the dish and bake for 30 minutes. Stir halfway through cooking.  Transfer caramelized apples in a bowl and let them cool down before assembling the tart.

To make vanilla cream, soak gelatin in cold water for 5 to 10 minutes. In a separate bowl, whisk egg yolks, sugar, and corn starch with a hand whisk. Heat milk, add a whole vanilla bean and infuse for 20 minutes in a covered container. Remove the bean and bring milk to a boil. Then pour hot milk into the egg yolks/sugar/starch mixture stirring constantly. Bring the mixture back to the pan and heat the mixture over medium heat for about one minute, stirring constantly. Remove the cream from heat, add the drained gelatin and mix. Transfer the cream to a bowl and let it cool down to 104 F/40 C or warm to touch. Gradually add the butter cut into small cubes and mix with the spatula. Cover the cream with plastic film in contact and refrigerate.

To make the caramel topping, place granulated sugar in a saucepan and heat over medium heat to get the caramel. Pour hot water (keep the pan out of the heat and be careful with splashing!) and heat the caramel syrup again for a few seconds. In a separate saucepan, make a clear glaze as directed (see note #3). Let the glaze cool for 5 to 10 minutes and whisk with the caramel syrup. Let it rest until it starts to thicken. Coat apples with the caramel topping using a silicone brush. Decorate the tart with edible flowers, gold sugar pearls, or edible gold leaf. Remove the tart from the pan before serving.