Homemade Blueberry Nutri Grain Bars

1. Preheat the oven to 350 degrees F. In a large bowl, mix the flour, oatmeal, cinnamon, and salt together. Add the butter and toss to coat. Add the egg yolks, yogurt, honey, and vanilla and mix until combined, adding 1 tablespoon of cold water at a time until the dough comes together and forms a ball. 2. Turn the dough out onto a floured surface. Roll out into a 1/8-inch thickness. Cut the dough into about 4" x 4 1/2" squares. Place a heaping tablespoon of jam down the center of each square, leaving about 1/4 inch border. Brush the borders with buttermilk. Fold one side up and over the filling and then pinch the dough together at either end. Do the same for the other side and use your fingers to seal the dough together at the seams. Carefully roll the bar over and place the seam side down on a baking sheet lined with parchment paper. Repeat with remaining dough.3. Cover the bars and place the baking sheet in the freezer for 10-15 minutes. Once chilled, brush the tops of the bars lightly with buttermilk and transfer to the oven, bake on the middle rack for 15-20 minutes or until lightly golden brown on top, do not over bake.4. Allow to cool 5-10 minutes, then carefully transfer the bars to a glass container with a lid, layering them between pieces of parchment paper. This will trap in heat and moisture, and slightly steam the bars, ensuring they remain soft. Store in an airtight container for up to 3 days or in the fridge for longer. These can also be wrapped in plastic wrap and frozen, thaw for 1 hour.