Note: If you are using pre-made dough, skip to step 4

1. Pour yeast package contents into a stand mixer bowl or large mixing bowl. In a heat-resistant bowl, warm ¾ cup of whole milk in the microwave for about 20 seconds. Add the warm milk to the mixing bowl with yeast (let sit for 5 minutes). Add the one egg plus one egg yolk, ¼ cup of sugar, ¾ teaspoon of salt, ¼ cup of sour cream, and ¼ cup of warm melted butter. Mix with a mixer or whisk for about one minute.
2. Slowly pour in 1 cup of flour at a time to the wet mixture, and mix on the lowest mixer setting until combined.
3. Change from standard mixer attachment to dough hook(s) on the mixer, then fully incorporate the dough for 3-5 minutes. If the dough needs more flour, add more until the dough is not overly sticky. Transfer the dough to a floured surface, knead for 2 minutes, and create a ball with the dough mixture. *SEE NOTE
4. Transfer the dough ball to a greased bowl (spray with a bit of cooking spray) and loosely cover with plastic wrap. Allow dough to rise for 90 minutes or until doubled in size.
5. Once the dough has doubled, place the dough on a floured surface and roll out the dough in a friendly 12x8 - 14x9 decent-sized rectangle-oval shape.
6. Spread the room temp butter on the dough, leaving a good 1/2 inch from the outside; spread the Blackberry jam on the butter, and then top with the brown sugar and the 1/4 teaspoon of cinnamon.
7. Then, as tight as you can, starting from the short side of the rolled-out dough, roll up the dough. Cut off 1 inch on each end of the rolled dough.
8. Cut the dough with a bread knife (or dental floss) into 1 -1/2-inch pieces until around six rolls.
9. Place the pieces in the greased large muffin tin. Cover with plastic wrap and let the mixture rise again for 30 minutes.
10. While the dough completes the second rise, preheat the oven to 350F.
11. Once the dough has risen, remove the plastic wrap and bake for 20-25 minutes in the oven or until golden brown. 
12. While the rolls are in the oven, combine the Glaze ingredients with a mixer on low until well combined, and set aside. Once the registrations are done, let cool for 5 minutes, then slather the frosting on top and serve.

NOTES: 

*If you do not have a  mixer and hook attachment, mix the dough with a rubber spatula/handheld mixer, then knead the dough by hand for 8 minutes until the dough is soft and supple*

If using a smaller muffin tin, can cut it into 12 even pieces (Cut the cylinder in half, then cut each half into thirds, then cut the thirds in half.

FYI: The rolls might look like popovers, do not worry, as they still taste good.

‍Storing the rolls to bake the next day:  Once you have completed step 9, place each roll in the muffin tin. Please do not allow them to rise again, cover the rolls with plastic wrap, and then cover the muffin tin with a damp tea cloth. Place in the refrigerator overnight. 

Once you are ready to bake the rolls, you will remove them from the refrigerator and allow them to come to room temperature (2 hours), and complete the second rise before baking. I do not suggest freezing the dough or glaze. 

Storing baked rolls: These rolls can be stored covered in an air-tight container or individually wrapped for 3 days.  Reheat them in the oven on 350F for about 5 minutes or until they are warm.