Make your dough. Add bread flour, chilled butter, baking powder, sugar, and salt to a food processor and pulse a few times, until the butter pieces are about the size of peas. If you don’t have a food processor, you can gently work the dough together with your hands or use a pastry cutter.
Add in the water a little at a time and pulse a few more times to incorporate til a ball is formed.
Shape and chill your dough. Move the dough to a baking mat or another clean surface and press it together until it forms a ball. Divide into two pieces and flatten each into a ½ inch thick rectangle, wrap with plastic wrap, and chill them in the fridge for at least an hour.
Meanwhile, preheat your oven to 350˚F.
Form your crackers. Roll your chilled dough into a circle about 9-10 inches in diameter. It should be about ⅛” thick. Aim for slightly thicker rather than thin if you’re not sure, as they will burn if they are too thin. Cut into rounds with your fluted pastry ring and carefully transfer to a parchment-lined baking sheet. The crackers don’t really expand, so you can space them closely together. Repeat with your other dough half.
Get your crackers ready for the oven. Using a skewer, poke some holes into your crackers. Regular Ritz crackers have 7 holes, and the sandwich crackers have 9. For authenticity’s sake, we went with 9, but you can do 2-4, since this is pretty time consuming. Beat an egg with 1 tablespoon of water, then brush lightly onto each cracker. Sprinkle crackers with a bit more kosher salt.
Bake your crackers. Move crackers to the oven and bake for around 15 minutes, or until outer edges of the crackers are golden brown.