Directions
1. Preheat the oven to 400ºF.
2. In a medium bowl combine the water, canola oil, eggs, peanut butter and vanilla; set aside.
3. In a large bowl whisk together the flour, cornmeal and oats. Make a well in the center of the flour mixture and pour in the wet ingredients. Stir well to combine. Add the blueberry mixture and stir until just combined.
4. On a well-floured surface roll the dough out to about 1/3 of an inch thickness. Using a cookie cutter cut out the treats and transfer to a baking sheet.
5. Bake 10 to 20 minutes or until desired crispness. 
6. Once cool spread some peanut butter between each cookie.
7. Store in an airtight container for a week or in the freezer up to up six months.