How to Make It
In a small bowl, whisk the egg with the egg yolk, crème fraîche and milk. In a large bowl, combine the 2 1/2 cups of flour with the sugar, baking powder, table salt and pepper. Using a pastry blender or 2 butter knives, cut the butter into the flour mixture until it resembles coarse meal. Add the egg mixture and stir with a wooden spoon until the dough is evenly moistened. Gather the dough into a ball and knead 2 or 3 times, just until it comes together.
Line 2 large baking sheets with parchment paper and dust them with flour. Transfer the dough to one of the baking sheets and press it into an 8-by-10-inch rectangle. Cover with plastic wrap and refrigerate for 1 hour.
Preheat the oven to 400°. Transfer the dough to a floured work surface and roll it out to an 11-inch square. Fold the square in half and roll it out again to an 11-inch square. Repeat the folding and rolling once more. Using a 2-inch round biscuit cutter, stamp out as many biscuits as possible. Gather the scraps, reroll and stamp out more biscuits.
Evenly space the biscuits on the lined baking sheets. Brush the tops with the cream and sprinkle with Maldon salt. Bake the biscuits in the upper and lower thirds of the oven for about 20 minutes, until golden; shift the baking sheets from top to bottom and front to back halfway through. Serve the biscuits warm.