Preheat oven to 425° F. Thaw the pie dough and berries.
Roll the pie dough into a 12" circle. Place on a baking sheet lightly coated with cooking spray.
In a medium bowl, combine the thawed berries and 2 tablespoons of sugar (or sugar substitute).
Arrange the berry mixture in the center of the dough leaving a 2" to 3" border. Fold the edges of dough in towards the center, pressing gently to seal. (Dough will only partially cover the berries.)
Melt the preserves by heating in the microwave 10 to 20 seconds.
Brush folded-in edges of the dough with melted preserves. Bake for 10 minutes; then reduce heat to 350° F. Bake an additional 20 minutes.
Remove galette from the oven and sprinkle with remaining 1/2 tablespoon sugar.
Serve warm or at room temperature. Cut into 6 wedges as you would a pie.