In a bowl, mix the flour, powdered sugar, and salt. Add the softened butter and mix until crumbly. Stir in vanilla and egg yolk, mix until a dough forms. Press into a tart pan and refrigerate for 30 minutes.

Bake the Crust

Preheat the oven to 350°F (175°C). Bake the crust for 15-20 minutes, or until lightly golden. Let it cool completely.

Macadamia Nut Jam

Cook the Jam

In a saucepan, combine chopped macadamia nuts, granulated sugar, lemon juice, and water. Cook over medium heat, stirring until the sugar dissolves. Bring to a boil, then reduce heat and simmer for 15 minutes until thickened. Let it cool.

Salted Caramel Mousse

Make the Caramel

In a saucepan, melt granulated sugar over medium heat until it turns amber. Add butter and stir until melted and smooth. Slowly whisk in heavy cream and sea salt. Allow to cool slightly.

Combine with Eggs

In a bowl, whisk the beaten eggs. Gradually add the warm caramel mixture into the eggs, whisking continuously to avoid scrambling. Let it cool completely.

Assembly

Assemble the Tart

Spread the macadamia nut jam evenly over the cooled tart crust. Pour the salted caramel mousse on top, smoothing it out. Refrigerate for at least 2 hours to set before serving.