Step 1

Preheat the oven to 220° C /200° Fan /Gas 7 /425° F.

Step 2

Cut two pieces of baking paper to fit the bases of two shallow baking trays each 31 x 21 cm. Cook in two batches if you only have one suitably sized tray.

Step 3

Put the flour, rosemary, garlic powder if using, salt and black pepper in a mixing bowl and stir together. Make a well in the centre.

Step 4

Stir the water and olive oil together then pour into the centre of the flour mixture.Start by stirring with a spoon to combine, then switch to your hands to bring together into a dough that leaves the bowl clean.Transfer to a clean work surface and briefly knead/fold into a smooth ball.Cut in half (use scales for accuracy) then set one half aside, covered with the upturned bowl so it doesn't dry out.

Step 5

Lightly flour one of the pieces of baking paper.Place one piece of dough on it, sprinkle with a little flour, and roll out very thinly (no more than 1-2 mm or the crackers will be hard rather than crispy) until it covers the paper.

Step 6

Neaten the edges of the dough with a knife, pastry wheel or pizza wheel plus a ruler if necessary.Cut the dough into squares or rectangles of your preferred size.

Step 7

Slide the paper and the uncooked crackers onto one of the baking trays.Prick the crackers all over with a fork.

Step 8

Put the crackers in the preheated oven and cook until crisp and golden (10-15 min). Check after 8 minutes: crackers at the edges of the tray may cook much quicker, so remove these to a cooling rack and return the rest to the oven.While the first tray is baking, roll and cut another batch with the remaining dough and cook as above.

Step 9

When done, crackers should be left on the cooling rack until completely cold before storing in an airtight container. Should keep for 2 weeks.