Crush the pretzels until they reach a fine consistency, similar to sand.

In a mixing bowl, combine the crushed pretzels, melted unsalted butter, and granulated sugar. Stir until mixed, resembling wet sand.

Press the pretzel mixture into an 8x8-inch tart pan to create an even layer. Refrigerate for 15 minutes.

Heat the heavy cream in a saucepan over medium heat until it simmers, about 5 minutes.

Remove from heat and stir in the chopped dark chocolate until fully melted and smooth.

Add in the pure vanilla extract and a pinch of flaky sea salt, stirring well to combine.

Pour the chocolate mixture over the chilled pretzel crust and smooth it out evenly. Sprinkle extra sea salt on top.

Chill in the refrigerator for at least 2 hours until set.

Slice into 9-12 pieces and serve chilled.