Place heavy cream in the freezer for 20-30 seconds. Mix yeast and sugar in a bowl, whisk in chilled cream, cover, and let sit in a warm place for 10-15 minutes until bubbly.
In a food processor, combine almond flour, coconut flour, psyllium husk, erythritol, salt, and baking powder. Add the egg, activated yeast mixture, and blend for 10-20 seconds.
Transfer dough to a bowl, shape it into a mass with a spatula, cover, and let it rise in a warm place for 1 hour.
Roll dough to ¼-inch thickness, cut into 20 squares, and let rest under cling film for 30 minutes.
Heat oil in a saucepan to 180°C (350°F). Fry 4-5 beignets at a time for about 1 minute per side, ensuring they puff up and turn golden.
Drain beignets on paper towels and repeat with remaining dough.
Sprinkle powdered erythritol over the beignets and serve warm with your favorite low-carb dip.