Place the chocolate sandwich cookies in a food processor and pulse until they become fine crumbs. Pour the melted butter over the crumbs and pulse again until the mixture is well-combined and resembles wet sand. Press the mixture firmly into the bottom and up the sides of a 9-inch tart pan with a removable bottom. Place the pan in the freezer for 10 minutes to set.

Using a sharp knife, finely chop the dark chocolate bars. Even pieces are important because they will melt more consistently. Place the chopped chocolate and the sea salt into a heat-proof glass or metal bowl and set aside.

Pour the heavy cream into a small saucepan over medium heat. Bring the cream to a gentle simmer, just until you see small bubbles forming around the edges of the pan. Do not let it reach a full, rolling boil, as this can cause the chocolate to separate.

Immediately pour the hot cream over the chopped chocolate. Let it sit undisturbed for about 5 minutes to allow the heat to melt the chocolate. Add the vanilla extract, then gently whisk the mixture starting from the center and moving outward until it is completely smooth, glossy, and dark.

Remove the tart crust from the freezer. Pour the chocolate ganache into the crust, spreading it evenly with a spatula if necessary. Tap the pan gently on the counter to remove any air bubbles. Refrigerate the tart for at least 2 to 4 hours, or until the filling is firm and set.

Just before serving, sprinkle the fresh pomegranate arils over the top of the set chocolate. You can arrange them in a decorative pattern or scatter them naturally. Remove the tart from the outer ring of the pan, slice with a warm knife, and serve chilled.