In the saucepan place butter, water, milk, sugar and salt. Over medium heat bring mixture to boil.
Remove from heat and add the sifted flour. Mix well with rubber spatula until it forms one smooth ball and no flour bits are visible. It should look like mashed potatoes.
Place the saucepan back on the stove and cook the dough for about 2-3 minutes over medium heat mixing constantly. It is ready when a skin forms on the bottom of the saucepan.
Remove the dough from the heat and place in the bowl of a stand mixer and let it cool slightly before mixing the eggs in.
Whisk eggs in the small bowl before adding to the dough. Add a small amount of egg at a time, consistently whisking after each addition. The consistency of the dough should be not too runny and not too firm, just right to pipe.
Preheat oven to 350oF.
Place the dough into pipping bag with round tip.
Pipe equal sized choux puffs on the baking mat. Make sure to leave enough space between puffs. Dust puffs with powdered sugar.
Take the craquelin sheet out from the freezer. Using round cookie cutter, cut out circles, slightly larger in diameter than the choux puffs you just pipped. Add craquelin circles on top of each choux puffs.
Bake choux puffs in the oven for 40-50minutes, do not open the door of the oven in first 30 minutes or until the choux are fully puffed. The puff should be golden in color and when you cut not wet in the middle.
Transfer choux puffs on the wire rack to cool completely.