Make the Biscuits. Preheat the oven to 450°F and line a baking sheet with parchment paper. Place the butter in the freezer for at least 30 minutes, or until frozen solid.

Combine heavy cream and apple cider vinegar in a small bowl, whisk together, and let sit for a few minutes to curdle cream.

In a large bowl, whisk together the brown rice flour, tapioca starch, potato starch, sorghum flour, baking powder, salt, baking soda, and xanthan gum. Remove the butter from the freezer and grate it coarsely with a box grater. Do this directly into the bowl of flours.

Mix the butter into the flour using your hands. Stir in the cream mixture with a wooden spoon or fork. The dough will be extremely shaggy. You'll need to knead it with your hands until it comes together into a dough. Don't worry if it seems too sticky, it will eventually become smooth.

Dust a work surface with brown rice flour. Transfer the dough onto the surface, and roll it into a rectangle that is three times as long as it is wide and about 1/2 inch thick. Fold the dough into thirds like an envelope, with one side into the center, then the other side on top of the other. Rotate the dough a half turn on the work surface and roll it out into a rectangle again and repeat the folding process. This is what helps the biscuits have flaky layers. Rotate the dough again and roll into a rectangle that is about 8x4 inches. It should be 1 1/2 to 2 inches thick. Cut the dough into 6 squares, or using a round cutter (about 3 inches) cut it into 6 rounds. A sharp-edged cutter or knife will help the biscuits to rise higher, but in a pinch, even a glass or jar will work.

Brush the beaten egg over the tops of the biscuits and sprinkle with raw (turbinado) sugar. Bake for 18 minutes, until golden brown. Transfer the baking sheet to a cooling rack, and let the biscuits cool on the pan for 5 minutes. Lift them off and let them cool completely on a rack.

Make the wine syrup. Combine the sugar, wine, blackberries and water in a medium saucepan over medium-high heat. Bring to a boil, stirring occasionally until sugar dissolves. Reduce heat to medium and simmer for about 20 minutes, or until the mixture is thick and syrupy and coats the back of a spoon. Remove from the heat and cool 15 minutes.

Transfer cooled blackberry mixture to a blender and puree. Pour into a bowl through a fine wire mesh sieve to remove the seeds. Stir in lemon juice and vanilla extract. Place in the refrigerator and chill at least 3 hours or overnight.

Make the whipped cream. Put the cream in a medium bowl and beat until soft peaks form. Add the sugar and continue beating for a few more minutes or until the cream holds stiff peaks. Fold in the vanilla extract. Chill until ready to use.

To assemble the shortcakes. Split each biscuit in half. Pile berries on the bottom half, top with whipped cream, drizzle with wine syrup and place the top of the biscuit back on top. Serve immediately with extra wine syrup on the side.