Process flour, sugar and salt in a food processor for 5 seconds until combined.
Scatter chilled butter over the top and process in short pulses until the mixture resembles wet sand.
Add egg yolk, vanilla and mascarpone and process until the dough just comes together.
Wrap the dough in plastic wrap and chill for 30 minutes.
Roll chilled dough into a rectangle or circle (depending on the shape of your tart pan). Gently ease the dough into the pan, press into the corners and cut off excess along the rim. Cover and chill for 15 minutes.
Preheat the oven to 160C.
Blind bake for 20 minutes, then remove the weights and paper, cover the edges with foil and bake for another 10-15 minutes until golden and cooked through.
Remove and cool to room temperature.
Salted caramel filling
Heat sugar and glucose in a small saucepan, stirring until sugar is dissolved. Continue to simmer on medium heat until the liquid turns a golden brown.
Take off the heat then pour in the cream. Stir until smooth.
Allow to cool slightly then whisk in butter and salt.
Fill the cooled tart shell with the caramel and chill for 1 hour to set.
Mandarin chocolate ganache filling
In a small saucepan, bring the cream to the boil, then immediately remove.
Add chocolate and let it melt in the hot cream for a minute. Stir until smooth and shiny.
While still stirring, add the butter, little pieces at a time, until completely combined.
Finally whisk in Triple Sec and mandarin juice.
Pour the ganache over the caramel in the tart shell. Chill for at least 2 hours until set.