Grease or parchment-line a baking sheet.
Turn the risen dough out on an lightly floured surface and divide it into 12 equal pieces. Using just enough flour to prevent sticking, roll each piece into a small ball.
Flatten one of the balls into 3 1/2 to 4-inch circle. Set the circle in a small bowl and spoon a rounded tablespoon of chocolate chips in the center of the dough. Pull the sides together around the chocolate, pinching well to create a good seal.
Turn the sealed bun into your hands and set the oval seam-side down on the prepared baking sheet. Repeat with the remaining dough and filling, spacing the buns several inches apart.
Cover the shaped buns with plastic wrap and let them rise until they're quite puffy, about 30 to 45 minutes. Alternatively, spritz the shaped buns with cooking spray, cover with plastic wrap, and let them rise in the refrigerator overnight. Before baking, let them rest at room temperature for about 30 minutes before proceeding.
Preheat oven to 375° F.
For the egg wash, whisk together the egg, water, and a pinch of salt. Right before baking, brush the tops lightly with the egg wash and sprinkle generously with Swedish pearl sugar.
Bake the rolls until golden brown, about 15 minutes. Let cool for at least 10 minutes before eating.