Homemade Cinnamon Toast Crunch

1. Preheat the oven to 350 degrees F. Make the cinnamon sugar. In small bowl, combine 1 tablespoon cinnamon and the sugar. 
2. In a food processor, combine the whole wheat flour, flour, remaining 1/2 teaspoon cinnamon, salt, and butter. Pulse until the mix clumps together to form pea-size balls. Add the vanilla, and 1/2 cup cold water, 1 tablespoon at a time, until the dough comes together and forms a ball. If the dough feels dry, add 1-2 tablespoons additional water.
3. Turn the dough out onto a floured surface and form into a ball. Divide the dough in half. Working with one piece of dough at a time, roll the dough as thin as you can, preferably an 1/8-inch thick (about the thickness of a quarter). Transfer the dough to a large piece of parchment paper. Brush the dough with melted butter and sprinkle generously with cinnamon sugar, gently pressing the sugar into the dough. Cut into 1/2-inch squares. Repeat with the remaining dough. 
4. Carefully transfer the parchment paper to a baking sheet. Separate the squares, spacing them a 1/2 inch apart. 
5. Bake 12-14 minutes, until golden brown. Let cool completely, then store in an airtight container for up to 1 week. Enjoy...with milk, a top ice cream, or simply by the handful.