In a food processor, pulse almonds until finely ground. Add sugar and pulse again. Add the flour and pulse until combined.
Immediately transfer dough to a 9-inch tart pan with a removable bottom. Using a measuring cup, evenly press dough in bottom and up sides of pan.
Bake in center of oven until golden brown and firm to the touch, about 20-25 minutes. Transfer to a wire rack to cool completely, about 1 hour.
Salted Caramel + Chocolate Ganache Filling
Warm the salted caramel in the microwave till runny. Pour evenly in the tart shell, and keep rotating till the insides (not edges) are covered with a thin layer of the caramel. Leave to cool in the refrigerator for 20 minutes.
In the mean time, make the ganache: Place chocolate in a large mixing bowl. In a small saucepan, bring cream to a boil. Pour hot cream, through a sieve, over chocolate. Stir until smooth and creamy in texture. Mix in 1 tsp vanilla, if using.
Pour chocolate mixture into center of cooled tart shell, over the salted caramel. Gently place in refrigerator to chill and set for 4 hours.
Place the tart over a glass or mug, the slowly release the tart ring. It should easily drop down. Now bring the tart onto a counter and with a sharp knife, gently release it from the removable bottom of the tart tin. This requires very minimal effort - but does require a gentle touch.
Slice with a sharp, slightly warm knife and enjoy.