Preheat your oven to 350°F (175°C) and line a 9x9-inch baking dish with parchment paper. Combine flour, powdered sugar, and salt in a food processor. Add cold butter and pulse until sandy. Whisk egg yolk, heavy cream, and vanilla, then mix into dry ingredients until crumbly. Press into the dish, prick with a fork, and chill for 20-30 minutes before baking.

Bake the crust for 15 minutes with pie weights, then remove the weights and bake for an additional 20 minutes until lightly browned. Allow to cool completely.

Bloom gelatin in cold water. Set up a double boiler; mix softened butter and sugar until creamy. Add egg yolks, mango puree, salt, and lemon juice, stirring constantly over simmering water for 15-25 minutes until thickened. Stir in melted gelatin and strain curd.

Pour mango curd over cooled crust and spread evenly. Warm raspberry jam and drop spoonfuls on curd; swirl gently with a knife.

Cover with plastic wrap and refrigerate for 4-6 hours or overnight. Ensure they are fully chilled for clean cuts.

Use a warm knife to slice bars neatly. Serve chilled for a refreshing treat.