Add the blueberries, sugar, and cornstarch to a medium pot.

Cook over medium heat for 20-25 minutes until thick and the jam measures out to about ¾ cup (180 ml).

Remove from the heat, transfer to a bowl and let the jam cool. Set aside 2 tablespoon of jam for the frosting.

To start, bloom your yeast. Mix your active dry yeast, sugar, and warm milk together and let sit for 10 minutes until foamy on top.

In a large bowl of a stand mixer with a whisk attachment, mix flour, salt and sugar together.

To the dry ingredients, add the whisked eggs, vanilla, lemon zest and softened butter and mix.

Add in the yeast mixture and mix until everything is blended. Switch to a dough hook and knead on medium speed for 7-10 minutes until the dough pulls away from the edges of the bowl.

Form the dough into a ball. Place the dough in a large, greased bowl. Cover and place in a warm place to rise for 1-1 ½ hours.

While the dough rises, make the filling by mixing butter, brown sugar, white sugar, lemon zest, lemon juice and salt together in a small bowl.

Grease a 9×13 inch casserole dish and set aside.

Once the dough has risen, roll it out on a lightly floured surface into about an 18 x 12 inch rectangle.

Spoon the lemon filling over the dough and spread it evenly.

Spoon the blueberry jam over the lemon filling and spread it evenly.

Roll up the dough tightly into a log shape, cut into 12 rolls about 1 ½ inches wide.

Place the rolls in the greased dish and pour room temperature heavy cream in between each roll.

Cover them and let them proof in a warm spot for about an hour.

Preheat the oven to 350 degrees F about 15 minutes before baking.

Once proofed, bake for 22-25 minutes, or until a light golden color.

While they bake, make the cream cheese frosting by mixing softened butter until pale and fluffy.

Add in the cream cheese and mix until combined.

Sift the powdered sugar into the mixture a little at a time and mix until all is combined.

Then add in the lemon zest and blueberry jam and combine until fluffy.

Let the rolls cool for 5 minutes, then cover the warm rolls with the cream cheese icing.