Preheat oven to 375 degrees.

Puree the spinach, oil salt, baking powder and water in a food processor or blender.

Combine the flour and the spinach mixture, either in the food processor, or a mixing bowl.

Knead the dough and form it into a nice ball.

Roll the dough out on a well floured surface. The dough should be rolled out very thin (like pasta dough).

Put the dough on a floured baking sheet.

Use a pastry cutter to cut the dough into squares.(a pizza cutter or knife will do if you don't have one)

Prick each cracker 2-3 times with a fork.

Bake for approximately 20 minutes. Thinner crackers and those on the edges will cook faster. Pull them out, and continue cooking those that are still soft. Crackers will crisp a bit more during cooling, but should be somewhat crisp when removed.

Crackers should be put directly on a kitchen towel to cool, to maintain their crispness.