Preheat the oven to 350°F and line a loaf pan with parchment. Stir the almond flour, cocoa powder, allulose, egg, melted butter, melted chocolate and salt into a thick batter, spread it in the pan and bake for 15 to 18 minutes until just set.
Let the brownie cool completely, then chill for 20 minutes and break it into bite size chunks. Slightly underbaked brownies stay perfectly fudgy once frozen.
Heat 1/2 cup of the heavy cream until steaming, then whisk in the cocoa powder and chopped chocolate until smooth. Let it cool to room temperature.
Beat the cream cheese, powdered allulose, vanilla extract and salt until smooth, then beat in the chocolate mixture until it looks like brownie batter.
Whip the remaining 1 1/2 cups heavy cream to stiff peaks and fold it into the chocolate mixture.
Fold in most of the brownie chunks, spread into a clean loaf pan and press the remaining chunks on top.
Cover and freeze for at least 6 hours. Let it soften for 10 minutes before scooping.