1) Preheat oven to 350 degrees F and line a cookie sheet with parchment paper.

2) Put the cake flour, sugar, coffee, walnuts, and salt in a food processor and process for about 10 seconds (or until the walnuts are well grounded).

3) Now put the mixture into a mixing bowl and add canola oil. Form a pasty dough, then separate the dough with your hands to form small crumbs.

4) Add the water and form into a clean dough. If you like raisins, you can combine it with the dough now.

5) Divide the dough into 16 pieces and roll each piece into a ball. Put each ball on a cookie sheet and bake at 350 degrees F for 25 minutes.

6) Let the cookies cool for about 20 minutes. Dust with powdered sugar before serving.