Preheat the oven to 180°C / 350°F. Line a baking sheet with parchment paper.
In a food processor, combine almond flour, coconut flour, powdered sweetener, xanthan gum, and salt. Pulse until well-mixed.
Add cream cheese, egg, melted butter, and vanilla extract. Pulse again until a sticky dough forms.
Shape the dough into a ball and wrap it in plastic. Place in the freezer for 10-15 minutes.
Make the filling: For the raspberry filling, place raspberries and sweetener in a non-stick pan over medium heat. Cook for 5 minutes, stirring occasionally.
Turn off the heat, stir in the xanthan gum, and allow it to cool completely.
Assemble the Keto Pop Tarts: Remove the dough from the freezer and divide it into two pieces. Roll out each piece and cut into 4 large rectangles or 8 smaller ones for a total of 8 /16 rectangles.
Place each rectangle on the baking sheet.
Lay half of the rectangles on a baking sheet. Place a tablespoon of the raspberry filling in the center of each. Cover with the remaining rectangles. Press the edges to seal, then place in the freezer for an additional 10 minutes.
If using the egg wash, beat the additional egg and brush over the tops of the pop tarts. Use a fork to further crimp and seal the edges. Cut an 'X' onto the top of each tart to allow steam to escape.
Bake in the preheated oven for 15 minutes or until golden brown.
Add the ingredients for the icing to a bowl and whisk until well combined.
For the icing, whisk together the powdered sweetener and heavy cream in a bowl until smooth.
Once pop tarts are removed from the oven and slightly cooled, spread the icing on top. Allow them to sit until the icing sets.