Cream the butter and sugar in a mixing bowl until light and fluffy. Add the maple extract and continue blending. Slowly beat in the flour and salt and add the blueberries until you have a slightly crumbly dough.
Transfer the dough to a floured surface and form into a ball. Wrap in plastic wrap and refrigerate for about 30 minutes.
When ready to bake, preheat oven to 350 degrees F. Roll the dough into a 1/4 inch thick rectangle and cut out using your favorite cookie cutter or just a floured drinking glass. Carefully lay the cookies on a parchment lined baking sheet, sprinkle with a little sugar, and bake for about 10 minutes, being careful not to overbake.
Allow the cookies to cool completely before serving.