In a bowl, combine the flour, sugar, baking powder, and baking soda until well blended.
In a separate bowl, whisk together the eggs and vanilla. Add the egg mixture to the flour mixture and mix well until all of the ingredients have been incorporated.
Next, fold in the blueberries and chocolate.
Turn the dough onto a lightly floured surface and knead until the dough is no longer sticky, then form two, 12” long log shapes and flatten down so that it is no higher than 1”.
Spray a baking sheet with cooking spray or line with parchment paper; then add the dough and bake at 325° F for 30 minutes.
Remove from oven and let cool, then slice diagonally into 1/2" thick slices and put them back on the baking sheet.
Bake an additional 8-10 minutes per side, then remove from the oven. Allow to cool completely before storing in an airtight container at room temperature for up to 2 weeks or in the freezer for up to 3 months. Makes 2 1/2 dz.