Preheat an oven to 300 F. Whisk together the dry ingredients in a small bowl. Then add the egg, melted butter, maple syrup, water, and vanilla. Mix until combined. It should be a thick dough.
Place the dough onto a Silpat and top it with a sheet of parchment paper. Using a rolling pin, roll the dough out into a thin rectangle (about ⅛”-¼” thick). If some of the dough starts rolling off the edge of the Silpat, trim it and press it unto another edge of dough.
Remove the parchment paper from the top and cut/score the graham crackers into any size square you like, for instance, 2x2”. Do not try to separate the crackers at this point. Prick them all with a fork several times.
Bake the crackers for 25 minutes until they are just beginning to brown. Remove them from the oven and let them cool until you can handle them. Leave your oven on. Using a spatula, cut along the score lines to separate the crackers. Keep them on the baking sheet. Right before placing them back into the oven, turn off the heat and place them into the oven to allow them to cool with the oven for an hour or so. Remove them from the oven and let them cool to room temperature.
Divide into eight portions and freeze for use in recipes, or consume immediately!