Preheat the oven to 350°F and line a baking sheet with parchment paper.
Stir together the heavy cream, water and apple cider vinegar and let it sit for 5 minutes until slightly thickened. This creates a simple keto buttermilk.
In a large bowl, whisk together the almond flour, coconut flour, psyllium husk powder, sweetener, baking powder, baking soda, salt and caraway seeds. Rub the cold butter into the flour with your fingertips until it looks like coarse crumbs with pea sized pieces.
Whisk the eggs into the buttermilk mixture, pour it into the dry ingredients and stir until a shaggy dough forms. Let it rest for 3 minutes to firm up.
Shape the dough into a round loaf about 7 inches wide and place it on the baking sheet. Snip a deep cross across the top with kitchen shears.
Bake for 40 to 45 minutes until golden brown and firm to the touch.
Cool for at least 30 minutes before slicing. Serve with plenty of salted butter or alongside a hearty stew.