Preheat oven to 375 degrees F. Line a sheet pan with parchment paper and set aside.
Add all dry ingredients into a food processor. Process for 15 seconds.
Add sliced cold butter, process for 10 seconds.
Add milk ( To be exact, measure milk with a 1/4-cup dry measuring cup instead of a liquid measuring cup). Prosee dough until it begins to gather together (about 20 seconds).
Dump dough one the kitchen counter, gently give 2-3 kneads to make dough into a smooth, flat, square disc.
Lightly dust the counter with some all purpose flour and roll dough (dust the top with some flour too) into a 12 X 12 inch square. Move dough often to ensure it does not stick to the counter and lightly dust with more flour if it starts sticking.
Cut into 1 X 1 inch squares ( I used a ruler and pizza wheel). Transfer squares onto the prepared baking sheet, spacing about 1/2-inch apart (crackers will not expand while baking).
Bake crackers (in the middle rack of the oven) for 23-26 minutes or until golden in color ( DON'T LET THEM TURN DARKER). Place pan on a wire rack to cool comleteely.
Crackers can be stored in an airtight conrtiner for 3-4 days.