Homemade Grape Nuts®

Preheat oven to 350 degrees F (175 degrees C). Line a baking sheet with waxed paper.

Combine flour, brown sugar, salt, baking soda, and cinnamon in a large bowl. Stir in buttermilk and vanilla extract; mix well. Pour mixture into prepared baking sheet and spread evenly with a spatula.

Bake in the preheated oven until browned and firm, 20 to 25 minutes. Cool patty in the baking sheet for 10 minutes before removing to cool completely on a wire rack.

Preheat oven to 275 degrees F (135 degrees C).

Break cooked patty into chunks and put through a meat grinder, using a coarse blade. Divide crumbs over two baking sheets.

Bake in the oven until dry, stirring every 10 minutes, about 30 minutes. Allow crumbs to cool completely and store in an airtight container.