1. Prepare the dough: In a large bowl, combine flour, salt, and baking soda. In a small bowl, whisk oil, maple syrup, egg, and vanilla until smooth. Combine liquid ingredients with dry and gently stir until a ball of dough forms. Wrap dough in plastic wrap and refrigerate 1 hour. (dough can be refrigerated up to 2 days)
2. Prepare the filling: Place dried blueberries and water in a food processor, process 30-60 seconds or until filling is smooth and pasty, scraping down sides as necessary. Store in refrigerator until ready to use (filling can be stored in refrigerator up to 4 days.)
3. Preheat oven to 350 F. Divide chilled dough in half. Between two sheets of parchment paper, roll half of dough out to 1/4 in thickness into a 6 x 12 rectangle. Spread half of prepared blueberry filling on half of dough rectangle to within 1/2 in of edges. . Fold un-spread half of dough over the blueberry filling and pinch edges to seal. Grip edges of parchment paper and transfer the log to a baking sheet. Repeat with remaining half of dough.
4. Bake dough logs in preheated oven 15 minutes, or until golden brown. Cool logs on pan 10 minutes, then, using a serrated knife, cut each log into 14 neat squares. Transfer blueberry newtons to a wire cooling rack to cool completely.
Yield: 28 blueberry newtons
Store blueberry newtons in refrigerator up to 5 days.