Line an 8 x 8-inch baking dish with parchment paper.
In a food processor, combine the oats, dates, almonds, vanilla and salt. Process until finely chopped. Add the milk, and continue processing until the mixture comes together. Press the mixture into the bottom of the baking dish, creating an even base layer.
Add all the ingredients for the cream filling to the food processor, and process until smooth and creamy, scraping down the sides as necessary. Spread the cream on top of the base in the baking dish. Freeze for 10 minutes.
In a small bowl, mix together all the topping ingredients until fully incorporated and smooth. Remove the dish from the freezer, and pour the chocolate mixture on top. Tilt the dish so that the chocolate covers the cream evenly. Sprinkle a handful of cacao nibs on top, if using.
Freeze until completely set, about 3 hours. Remove from freezer, and let sit for 5 minutes before slicing into squares.