Raspberry-Swirl Sweet Rolls

In winter, individual quick-freeze (IQF) fruit, such as those sold at Cascadian Farm, is often an excellent alternative to fresh fruit shipped in the United States. These soft, fluffy yeast rolls combine perfectly with IQF raspberries — a fun highlight of the cinnamon roll.
In a small saucepan, heat the milk over medium-low heat to 95°C. Pour the warm milk into the bowl of a stationary electric mixer equipped with a dough hook and stir in the sugar and yeast. Let stand until the yeast is frothy, about 5 minutes. Add the softened butter, eggs, grated lemon zest and sea salt. Add the flour and beat on medium speed until a soft dough forms, about 3 minutes. Increase the speed to medium-high and beat until the dough is soft, about 10 minutes longer.Place the dough on a lightly floured surface and knead it with your hands 2-3 times. Shape the dough into a ball and transfer it to a lightly oiled bowl. Cover the dough with plastic wrap and let it stand in a warm place until it doubles in volume, 1 to 2 hours.Line the bottom of a 9-by-13-inch baking dish with parchment paper so that the paper reaches the short sides. Brush the paper and sides of the mold with oil. Place the dough on a lightly floured work surface and, using a rolling pin, roll it out into a 10-by-24-inch rectangle.In a medium bowl, combine the frozen raspberries with the sugar and cornstarch. Spread the raspberry filling evenly over the dough. Roll out the dough tightly to form a 24-inch-long log. Working quickly, cut the block into quarters. Cut each quarter into 4 slices and place them on a baking dish with the side facing up. Scrape the berries and juice off the work surface and place on a baking dish between the rolls. Cover the rolls and let them rise in a warm place until they are puffy and fill the baking dish, about 2 hours.Preheat the oven to 425 degrees. Bake the rolls for about 25 minutes, until they are golden and the berries begin to bubble. Transfer the pan to a wire rack to cool for 30 minutes.In a small bowl, whisk together the powdered sugar, butter, and heavy cream until the frosting is thick and spreading.Flip the rolls onto a wire rack and remove the parchment paper. Flip the rolls onto a platter. Spread the icing on each roll and spread with a spatula. Serve warm or at room temperature.