Remove pits from the dates. If the dates are very firm, microwave them a few seconds to soften.

Place the nuts (walnuts, almonds, or pecans), pitted dates, cocoa powder, and salt into a food processor. Pulse until the mixture forms small, even crumbs that hold together when pressed. (Do not use a blender — it can make the mixture overly sticky.)

Transfer the crust mixture into a 9-inch tart pan or a parchment-lined pie pan. Press the mixture down very firmly and evenly across the bottom and, if using a tart pan, up the sides to form the crust.

Heat the canned coconut milk or coconut cream in a small saucepan over medium heat just until it begins to steam and small bubbles form at the edges (barely boiling). Remove from heat immediately.

Add the chocolate chips to the hot coconut milk/cream and stir until the chocolate is fully melted and the filling is smooth.

Pour the chocolate filling into the prepared crust and smooth the top with a spatula.

For firmest results, refrigerate the tart overnight. Alternatively, freeze the tart for a few hours until firm enough to slice.

If the tart is still too soft to cut clean slices after refrigeration, freeze for about 30 minutes to firm it up.

Store leftovers covered in the refrigerator or the freezer.