In a food processor, add together both flours, sugar, salt, cinnamon, and baking powder. Pulse 2 - 3 times to mix.
Add in the cubed butter and pulse about 5 - 6 times or until the mixture resembles coarse meal.
Add in the egg, molasses, and honey. Pulse until well-combined.
Add in the milk and pulse until the dough comes together in a ball.
Turn out the dough onto plastic wrap. Form into a disc and wrap tightly.
Chill for about an hour, then divide the dough in half. Preheat the oven to 300 degrees F.
Roll out half the dough between two sheets of parchment paper so it forms a large rectangle. Trim the edges so they are straight, then cut rectangles about 2 x 3 inches. Prick the rectangles with a fork a few times.
Repeat with the other half of the dough.
Take any trimmings and repeat until you’ve used up all the dough.
Bake the graham crackers for about 20 - 25 minutes, or until the crackers are slightly lighter in color.
Allow to cool completely on the baking sheets.
Break apart the graham crackers along where you cut.