In a medium saucepan, combine frozen blueberries, granulated sugar, and corn starch. Cook over medium heat for 20-25 minutes, stirring occasionally, until thickened. Let it cool completely, reserving some for frosting.

Warm whole milk to about 110°F, then sprinkle active dry yeast and a pinch of sugar. Let it bloom for 10 minutes.

In a large mixing bowl, blend all-purpose flour, salt, and remaining sugar. Stir in eggs, lemon zest, softened butter, and yeast mixture until combined.

Transfer to a floured surface and knead by hand or with a stand mixer for 7-10 minutes until smooth and elastic.

Shape dough into a ball, place in a greased bowl, cover, and let rise until doubled, about 1 to 1.5 hours.

Mix softened butter, brown sugar, lemon zest, lemon juice, and salt in a small bowl to create the filling.

After rising, punch down the dough and roll it to an 18x12-inch rectangle. Spread lemon filling, leaving a border, dollop blueberry jam on top.

Starting from one edge, tightly roll into a log and slice into 12 equal pieces. Place in a greased baking dish.

Pour room temperature heavy cream between rolls. Cover and let rise until doubled, about 1 hour.

Preheat oven to 350°F (175°C). Bake for 22-25 minutes until lightly golden and filling is bubbling.

Prepare frosting by beating cream cheese and butter until creamy, then mix in powdered sugar, lemon zest, and reserved blueberry jam.

Once rolls cool for about 10 minutes, spread cream cheese frosting on top.