In a bowl of a stand mixer fitted with a paddle attachment, remove the YEAST PACKETS from the Sweet Dough Mix and add the flour to the bowl. Add the yeast into the flour and whisk to combine.
Melt butter and add warm milk. Whisk until combined. Temperature should be between 105º - 110º. Do not exceed 110º as it will kill the yeast. Add lightly beaten eggs and mix.
With mixer running on low, add wet ingredients into dry ingredients. Once completely combined, turn mixer up to about medium or medium high and beat for 5 minutes. The dough should look sticky but smooth in texture.
Remove paddle attachment. Scrape dough together into a rough ball or mound. Spray a new bowl with cooking oil spray. Place mound of dough, cover with plastic wrap and place in warm, draft-free area for 1.5 to 2 hours to rise. Once risen, immediately chill for at least two hours, preferably overnight so the dough stiffens a little and easier to handle. ALTERNATIVELY: Cover dough with plastic wrap and let dough rise on counter for 30 minutes and immediately place in the fridge overnight.
On heavily floured surface, knead dough into a smooth ball, adding extra flour as needed until dough is no longer sticky (a little sticking is normal). Roll out to 18-inch by about 10-inch rectangle (about 1/4 to 1/2 inch thick). It doesn't need to be perfect.
Using a spatula, spread an even coat of blueberry jam on the dough, sprinkle frozen blueberries and the lemon zest.
Roll up jelly roll style and pinch seam to close. Flip over so seam is down and cut using dental floss (unflavored), a serrated knife or bench scraper into 1 1/2-2 inch rolls. You should get about 8 large rolls or up to 12 medium rolls.
Place rolls into lightly sprayed greased 9 x 13 pain (or any casserole style dish) and cover with plastic wrap. Let rise in warm, draft-free area until almost doubled in size. About 1-1 ½ hrs.
Optional Before Baking, pour the Heavy Cream on top making sure all the tops are poured over.
While rolls are cooling, whisk glaze ingredients in small bowl and drizzle over rolls.