Preheat oven to 350°F. Spread hazelnuts on a baking sheet. Roast for 10 minutes, until nuts are lightly toasted.
Carefully add warm hazelnuts to a high-powered small food processor. Process for a few seconds, until the hazelnuts become fine pieces. Add Splenda Sweetener, salt, cocoa powder, vanilla, and nut milk. Blend again. Mixture should be smooth, creamy, and velvety thick. Scrape down the sides and blend once more. If it is too thick, add another splash of nut milk and blend again.
Enjoy immediately, or scoop into an air-tight container and store in the refrigerator. Use within a week.