Makes 1 dozen squares

Preliminaries: Stir flour, cinnamon, and nutmeg together; set aside. Place sugars and butter in a bowl; toss to coat the butter with the sugar. Add flour mixture and work with fingertips to create a crumbly mixture. Set streusel aside. Position oven racks to divide oven into thirds, and preheat to 425°F. Line two baking sheets with parchment paper and dust with cornmeal. Fill a spray bottle with water.

Working with one piece of dough at a time, gently shape into a 10-inch square, and cut each square into quarters. Transfer the pastries to baking sheets. Use a single-edge razor blade to cut a crosshatch pattern in the center of each piece. Lightly press a few berries into each piece and top with streusel. Allow the fougasse to rest for 10 minutes. Bake 20 to 25 minutes, spraying the oven with water three times during the first 8 minutes of baking; the pastries should be golden brown. Transfer to a rack and cool before serving.