Place the maple syrup, sugar, and salt in a medium saucepan and stir to combine them. Add the butter, place the saucepan over med-high heat, and bring mixture to a boil, stirring often. Remove the saucepan from the heat and transfer the mixture to a large mixing bowl; add the sultanas & allow it to cool for 20 minutes. Whisk in heavy cream, followed by the egg and egg yolk. 

Preheat the oven to 180 Degrees. 

Place the tart shell on a baking sheet to catch any drips. Distribute the pine nuts evenly over the bottom of the tart shell and pour the custard into the shell until it reaches the top of the crust. Bake for 30-45 minutes, or until both the crust and the filling have turned light golden brown and the custard is set but still jiggly.  

Serve the tart while still slightly warm, or cool it and serve at room temperature. Leftovers will keep, wrapped in plastic, for a few days in the refrigerator.