In a bowl mix the butter, room temperature, and the sugar until light and fluffy.
Add the flour and cocoa shifted, the salt and the baking soda and mix until you have your cookie dough.
Cool the cookie dough into the fridge for some hours, covered with plastic wrap, you can form a log to form your cookies just cutting them with a knife.
Prepare our working surface with some flour and cut your cookies with a knife or extending the cookie dough with a rol and shipping them with a cookie cutter. Cookies must be 3 mm thick (1/8 inch).
Preheat the oven 345º Fahrenheit (180º Celsius)
Place the cookies on the cookie tray and bake them for 10-15minutes.
Let the cookies cool, fill with chocolae praline, and enjoy!