Preheat oven to 400 degrees. Soften cream cheese and combine with lemon juice, vanilla, and sweetener and egg yolk using a whisk or electric mixer. Set aside in the fridge until you are ready with the dough. Measure out almond flour, coconut flour, and baking powder. Combine well with a whisk. Melt 4 tbsp butter and add vanilla and sweetener. Stir. Melt 1 1/4 cup shredded mozzarella cheese in the microwave (30% power for 2 minutes with a 1200 watt microwave). Combine all the ingredients and add an egg. Stir until batter is combined and the cheese and dough are completely mixed. Use your hands or a spatula to press and fold the cheese and the batter together. Reheat for 10 seconds in the microwave. Press and fold some more until 99% of the dough is all one color. (Tip-this gets sticky and if you wet your hands a little it helps tremendously. The water from your hands will stop the stickiness on the outside of the dough making it very easy to roll out.) Reheat dough for 10 seconds and roll out into a square the approximate length of a rolling pin and slice into four quarters with a pizza slicer. Fold the corners into the center repeating with all four squares. Pipe filling (or spoon it on top!) into the center of each danish. Bake for 10-12 minutes. (Check on this at 10 minutes and make sure to remove it from the oven as soon as it has a deep golden brown color! Just slightly past 13 minutes and 2 of mine did get burnt. Definitely keep an eye on it.) Soften cream cheese in the microwave and add powdered sweetener, heavy cream and vanilla. Mix well with a whisk and pour into a ziploc bag. Cut a tiny hole in the corner and pipe onto each danish.