Stir together the flour and salt in a medium bowl; set aside.

In a large mixing bowl, cream the softened butter using an electric mixer until smooth. Add the powdered sugar and continue beating until light and fluffy.

Add the egg to the butter mixture and beat until everything comes together smoothly.

Pour in the flour mixture and mix on low speed just until you have a crumbly, soft dough.

Press the dough gently into a flat disc, wrap it in plastic wrap, and chill in the fridge for a couple of hours or overnight for best results.

On a floured surface, roll out the chilled dough until thin. Use a scalloped cookie cutter to cut out rounds for your tart shells.

Place each dough round over a muffin pan cavity and, using your knuckle, gently press the dough down so it lines the sides and bottom of each cup. Patch any tears with a bit more dough.

Chill the filled muffin pan again while the oven preheats. This helps the shells keep their shape.

Line the dough shells with muffin liners and add baking weights or uncooked rice to help keep the shape. Bake until the edges are golden brown.

After baking, remove the liners and let tart shells cool in the pan briefly before transferring them to a rack to cool fully.

For the filling, add chopped chocolate to a heat-safe bowl. Warm the cream until just simmering, then pour it over the chocolate. Let it sit briefly, then stir until you have a smooth ganache.

Allow the ganache to cool slightly so it thickens but stays pourable. Spoon or pipe the ganache into each cooled tart shell, filling about three-quarters full.

To make the whipped cream topping, beat together heavy cream, powdered sugar, and vanilla extract until it forms firm peaks—the texture should hold its shape and look billowy.

Pipe a generous dollop of whipped cream on some of the tarts for classic creaminess.

Top remaining tarts with fresh fruits or finish with a sprinkle of flaky salt for a sweet-salty bite.