1. Preheat oven to 375 degrees. Mix the flour, baking powder and salt in a food processor until smooth.
2. Add the butter and mix until the mixture resembles a coarse meal.
3. Transfer the mixture to a large bowl and add the heavy cream in a slow, steady stream, stirring with a wooden spoon until the dough forms.
4. Divide the dough into 9 pieces, form each into a ball and flatten slightly. Put aside.
5. In medium bowl, combine blueberries, sugar, cornstarch and cinnamon; toss gently to coat well.
6. Transfer the mixture to an 8 inch square baking dish. Top blueberry mixture with balls of dough, spacing evenly.
7. Brush the dough with heavy cream and sprinkle with abrasive sugar.
8. Bake until berries are bubbly in center and cookies are golden brown, about 55 minutes.
9. Transfer the dish to a wire rack and let cool slightly, about 30 minutes.
Enjoy !
