5 tbsp. Butter, plus more for buttering the pan and brushing on top
For the Filling
2 tsp. Lemon Zest, (from 2 medium sized lemons)
⅔ cup Sugar
¼ cup melted Butter
1½ cups Blueberry
For the Lemon Glaze
2 cups Confectioners Sugar
2 tbsp. Lemon Juice
2 tbsp. Heavy Cream, (or milk, or half and half)
1 tsp. Lemon Zest, (from 1 medium sized lemon)
1 tsp. Vanilla
Instructions
Warm milk and melt butter, set aside. Place 3½ cups of All-Purpose Flour in the bowl of stand mixer, and add yeast, salt, sugar, milk, egg, and melted butter. Start on low and increase to medium; beat until smooth, about 1 minute.
Roll or press dough into approximately 16"x12" rectangle. The dough should be about 1/4 inch think.
In a small bowl mix together 2 tsp lemon zest and 2/3 cup sugar. Using fingers or back of spoon against the bowl, thoroughly mix zest until zest melts into the sugar.
Using pastry brush, brush butter onto rolled out dough into even later. Sprinkle lemon sugar mixture over dough followed by blueberries. Then roll the dough from the long edge, ensuring that the final seam ends up on the counter. Using sharp knife, cut into 12 even pieces.
Thoroughly butter a 8.5"x11" baking pan, and space rolls evenly in the pan. Cover and allow to double in size in warm draft free spot (~1 to 1½ hours). If making ahead, rolls can be refrigerated over night and allowed to rise the next morning, just allow extra half hour for rising.
Preheat oven to 375°F with rack in upper third of the oven. Brush rolls with melted butter. Bake for about 40 minutes until golden brown (180° interior temp). Allow rolls to cool for 5-10 minutes.
While rolls are cooling, mix together confectioners sugar, lemon juice, heavy cream (or milk), 1tsp lemon zest, and vanilla to create glaze.
Once rolls cool down slightly, but before sugar begins to harden, flip out of pan onto tray. Drizzle top generously with lemon glaze, and serve.