In a bowl, mix together flour, salt and baking powder.
Mix in melted butter and add water.
Mix and pour onto a lightly floured surface.
Press together and knead until the dough is soft and smooth.
Wrap in plastic wrap and rest for 30 minutes.
Line 2 baking sheets with parchment paper, brown paper or aluminium foil. Set aside.
Press the dough lightly with the rolling pin at the centre and roll outwards.
Roll in one direction a couple of times then lift it up and rotate a quarter turn and roll.
Keep rolling and rotating till you get your desired thickness.
Roll out the dough to 1/8" thickness for the fried empanadas and to 1/4" thickness for the baked ones.
If the dough is getting sticky, lift it up, sprinkle flour on the countertop, the rolling pin and lightly on top of the dough.
Using a pie cutter or a circular plate, cut out circles to your desired size between 6-8 inches in diameter.
Place pie filling on half of the circle making sure to leave some space around the edges.
Rub a little egg around the edges.
Fold the empty side of the pastry over the filling to cover it and meet the edge on the other side of the circle to form the letter D.
Crimp the outer edges by hand or with the tines of a fork.
If using a pie dough cutter, place the circle on the side with the serrated zigzag edges, put some pie filling and close pressing hard to seal.
Place individual pies on the prepared sheet.