In a large mixing bowl, combine the almond flour, sifted gluten-free all-purpose flour, fine sea salt, powdered sugar, and gluten-free baking powder. Add the butter and rub it into the dry ingredients with your fingers until the mixture resembles coarse crumbs.

Add the eggs and sour cream, mixing until a soft dough forms. If the dough is too sticky to touch, add a bit more gluten-free flour. Form the dough into a disk, wrap it in plastic wrap, and refrigerate for at least 1 hour.

In a small bowl, mix the cranberry jam and mixed berry jam. Set aside.

Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.

On a lightly floured surface, roll out the dough to about ⅕-inch (5mm) thickness. Cut the dough into squares approximately 3-4 inches on each side. Place a small spoonful of the jam mixture in the center of each square. From this amount of dough, you should get approximately 25-30 cookies of this size.

To form the envelope shape, bring the corners of each dough square towards the center over the jam, pinching them lightly to seal. Place the shaped cookies onto the prepared baking sheet, leaving some space between each cookie.

Bake in the preheated oven for 15 minutes, or until the edges are lightly golden. Remove from the oven and allow the cookies to cool on the baking sheet for a few minutes before transferring them to a wire rack to cool completely.

Dust the cookies with a little powdered sugar and serve. The cookies can be stored for up to 3 days in an airtight container.