To make the crust, whisk together the flour, sugar, and salt in a medium size bowl. Toss in the cold, cubed butter and then use your fingers or a dough cutter, work the butter into the flour mixture. Try to work quickly and break the butter down into the flour mixture.
Create a well in the butter and flour mixture and pour in the cold buttermilk + hazelnut liquor. Use a fork to bring the dough together. On a lightly floured work surface, dump out the dough mixture. It will be moist and shaggy. Divide the dough in two and gently knead each dough into round, flat disks. Wrap each disk in plastic wrap and refrigerate for 1 hour or freeze for 30 minutes. Using the fridge works best.
Preheat the oven to 350 degrees F. Once the dough has been chilled, roll out one round at a time, leaving the other round in the fridge. On a lightly floured surface, roll out each piecrust to a 13-inch round. It is helpful if you can roll one crust into a 14 or 15 inch round. Lightly flour the two rounds and place them on top of each other. Cut the circle into 8 wedges, like a pizza, and place 4 wedges each of the two parchment-lined baking sheets. Remove the top wedge of dough and then divide the chocolate pieces evenly among each triangle, breaking them to fit within the triangle and leaving a 1/2-inch border on the sides and a 1 1/2-inch border at the wide end. Sprinkle the instant coffee evenly over each triangle and then sprinkle each triangle lightly with salt. Brush the borders lightly with the beaten egg. Cover with the top triangle, pressing the side edges firmly to seal. At the wide end of each wedge, fold the crust over and crimp decoratively to seal. Brush with more egg and then generously sprinkle with granulated sugar sugar or raw sugar. Cut 2 slits on top of each turnover.
Bake the turnovers until the crust is deep golden brown and the chocolate is melted, 25-30 minutes.
Meanwhile, make the whipped cream. Add the heavy cream to a large bowl and whisk until soft peaks form. Add the powdered sugar, hazelnut liquor and pinch of salt. Whisk until combined. Store in the fridge until ready to use.
To make the almonds, heat the butter in a skillet. Add the almonds and cook until toasted, about 5 minutes. Remove from the heat and stir in the hazelnut liquor and pinch of salt.
Once the turnovers are done remove them from the oven and let cool 5 minutes. Transfer the turnovers, by lifting up the parchment paper, onto cooling racks. Dust with powdered sugar. Serve warm (best this way!) or at room temperature with a dollop of whipped cream.
*Pie Crust adapted from [Joy The Baker | http://joythebaker.com/2014/11/five-tips-best-butter-pie-crust-scratch/].