1Make dough: In a small saucepan, warm milk over low heat until its about 95 degrees. Pour milk into a large bowl and stir in sugar and yeast. Let stand until the yeast is foamy about 5 mins. Add butter, eggs, lemon zest and salt. Add flour and beat at meium speed until a soft dough forms. Increase speed to medium to high for about 10 mins. Scrape dowugh onto lightly floured surface and knead 2 or 3 times. Form dough into a ball and transfer to a lightly buttered bowl (spray with cooking spray). Cover with plastive wrap in a warm place until doubled, about 1-2hrs.
2Butter or spray a 9x13 pan. Turn dough onto a lightly floured surface and roll into a 10x24 in. rectangle.
3Make filling: In a medium bowl, toss frozen rasberries with sugar and cornstarch. Spread the filling evenly over dough. Tightly roll up the dough to form a 24 in. long log. Cut log into quarters. Cut each quarter into 4 slices and arrange them in pan. Scrape any berries and juice from the work surgace into pan between the rolls. Cover rolls and let rise in a warm places until the are puffy and have filled the pan, about 2hrs.
4Heat oven to 425. Bake rolls for about 25 mins until they are golden brown and berries are bubbling. Cool for 30 mins.
5Make Glace: In a small bowl, whisk powder sugar with better and milk until glaze is spreadable and thick.
6Invert rolls onto a rack or I used a cookie sheet. Spread glaze over rolls.