Preheat the oven to 425 degrees F. Line a sheet pan with parchment paper.
In the bowl of an electric mixer fitted with the paddle attachment, combine the flour, the 2 tablespoons granulated sugar, the baking powder and salt. Add the butter and mix at low speed just until the butter is the size of peas. In a 2-cup measuring cup, whisk together the heavy cream, eggs and orange zest. With the mixer on low, add the cream mixture to the flour mixture and mix just until combined. The dough will be very sticky.
Heavily flour a cutting board. Mix the dough with a rubber spatula to be sure all of the dry ingredients at the bottom of the bowl are incorporated. Transfer to a board and knead lightly into a disk, adding just enough flour to keep the dough from sticking. Roll or pat the dough 3/4 to 1 inch thick. Cut circles of dough with a plain 3-inch round cutter and transfer to the prepared sheet pan. Chill for 30 minutes. Brush the tops with the egg wash and sprinkle with the turbinado sugar. Bake for 18 to 20 minutes, until the tops are browned and spring back when touched. Set aside to cool for 10 minutes.
Meanwhile, combine the strawberries and the 1/4 cup granulated sugar in a medium bowl. Set aside at room temperature for 30 minutes. Carefully fold in the raspberries and set aside for another 15 minutes to macerate. In a separate bowl, whisk together the yogurt and honey, cover and refrigerate.
To assemble, split each shortcake in half horizontally and place the bottoms on dessert plates. Spoon the yogurt mixture on each cake and spoon the berries and their juices on top. Place the shortcake tops over the berries. Sprinkle with extra grated orange zest, garnish with a sprig of mint and serve.
You can split the shortcakes with a knife, but they're prettier with jagged edges; split them with a fork, as you would an English muffin.