For the sweet pastry, In a food mixer, combine the flour, butter and sugar until breadcrumbs, add the egg yolks and mix until combined, you may need to add an extra egg yolk if the ones used are on the small side. Knead into a ball, wrap in cling film and leave in the fridge to rest for 30 minutes.
For the frangipane, cream together the butter and sugar until pale
Beat in the eggs, one at a time, until combined. Fold in the almonds, flour and almond extract and rum (if using it) and beat for a further minute. Fold in the diced marzipan
Preheat the oven to 160C fan assisted/180C normal oven/Gas Mark 4
Roll the pastry out large enough to fill the tart case you are using. Place the pastry in the tart case making sure that any small holes are filled with excess pastry to prevent the mixture from escaping while cooking, leaving some pastry over hanging the tart case to allow for shrinkage.
Place a layer of cling film over the pastry filled tart case and fill with uncooked rice or pasta (baking beans can be used if you have them) and bake the pastry case blind for 10 minutes. Remove the pastry case from the oven and carefully remove the cling film and rice, pasta or baking beans and spread the cherry conserve over the base
Spread almond mixture on top of the conserve and sprinkle with the flaked almonds – it may be easier to pipe the almond filling over the conserve if you have a piping bag to hand. Bake for a further 1 - 1.5 hours or until the almond filling is golden brown.
Allow the tart to cool slightly and place in the fridge to cool completely before trimming off the excess pastry using the edge of a sharp knife. Using the sugar, make an icing using a small amount of water to create a thick and smooth consistency. Pipe the icing over the tart in a zigzag pattern.