Preheat your oven to 350°F (175°C). In a food processor, combine all-purpose flour, powdered sugar, and salt. Add cold butter, processing until you achieve a sandy texture. Mix egg yolks, heavy cream, and vanilla extract before adding to the processor. Pulse until combined, press the dough into a lined baking dish, and chill for 20-30 minutes.

Cover the chilled crust with foil and weigh it down with pie weights or beans. Bake for 15 minutes, then remove the weights and foil, baking for another 20 minutes until golden brown. Let it cool completely.

In a small bowl, bloom gelatin in cold water. In a double boiler, combine softened butter and granulated sugar, stirring until smooth. Whisk in the egg yolks, mango puree, and lemon juice until thickened, which should take about 15-25 minutes. Stir in softened gelatin and strain if necessary for a smoother texture.

Spread the smooth mango curd over the cooled shortbread crust. Drop spoonfuls of warmed raspberry jam across the top and swirl gently with a knife to create a marbled effect.

Refrigerate the assembled bars until fully set, which usually takes about 4-6 hours, or overnight for best results.

Once set, carefully run a knife along the edges, lift out the bars, and slice with a warm knife for perfectly clean cuts.