Place the butter in a bowl and beat until soft and smooth, add the icing sugar and cream the ingredients together until light and smooth.
Gradually mix in the eggs making sure they become fully incorporated, add in the flour and salt and mix till it becomes one big mass.
Turn the pastry out on to a work surface, mix it all together and then shape it into a block, cover with cling-film and refrigerate the pastry for 30 minutes to an hour.
Put the chopped hazelnuts in a food processor or mini chopper and blitz until they are fine (don't blend them too much or they'll turn to nut butter).
Place the butter in the bowl of a stand mixer fitted with the beater attachment and mix until it is very soft.
Keep the mixer running, add the sugar, hazelnuts and ground almonds, it will form a thick paste. Add the flour and continue to mix, finally add the eggs and the brandy. Mix until the whole thing combines together and then place the frangipane in a disposable piping bag and chill it in the fridge while you roll out the pastry.
TO ASSEMBLE THE TARTS
Pre-heat the oven to 180C Fan, if using pastry rings, line a baking tray with a silicone mat, grease the rings and place them on the mat. If using a loose bottomed tin or tins, grease the tin(s) and place them on a baking tray.
Take the pastry out of the fridge, warm it a little in your hands and then roll it out on a lightly floured surface, until it's the same thickness as a pound coin or around 3-4mm.
If using individual tins, cut out pieces of pastry using a knife and lay them over the tins, pressing the pastry into the sides of the tin, using a rolling pin, roll over the top of the tin and then remove the excess pastry from the outside of the tin. Gently press the pastry into the sides of the tin so that it will stay put.
You will need to roll up the scraps of pastry and re-roll it to get the number of cases you need. If using one large tin, simply roll the pastry out to a thickness of 3-4mm and then lay it over the large greased tin and press it into the sides of the tin, use a rolling pin to remove the excess.
Place the pastry in the fridge to chill for another 30 mins.
Take the pastry from the fridge and put a generous amount of jam in the bottom of the pastry case. Spread the jam out evenly and then cut the tip off the disposable piping bag and pipe a layer of frangipane on top of the jam.
Don't be tempted to overfill the tarts with the frangipane as it puffs up while it bakes, so fill the tarts to just below the pastry - you may find you have some frangipane leftover.
Bake the tarts for 30 minutes or until golden and puffed up.
Place 15g sugar and the pectin in a small bowl and mix together. Put the milk, 35g sugar and butter in a small saucepan and bring to the boil. Take off the heat and add the flour, mix until fully combined.
Line a baking tray with a non-stick silicone mat and using a stepped palette knife spread the tuile mixture thinly, sprinkle with the chopped and roasted hazelnuts and then cover with another silicone baking mat. Bake for 8-10 minutes until golden brown.
Leave to cool and then remove the baking mat and snap the tuile into pieces - this can be stored in an airtight container for 2-3 days.
Mix the mascarpone with the maple syrup to taste and then taking a spoon make a quenelle of the mascarpone and top the cooled hazelnut tarts with the mascarpone and place a shard of tuile on the top.