For the dough: Add milk, butter, and sugar to a small pot; mix and warm up over medium heat just until butter melts; set aside. Add the strawberry kefir, flour, yeast, salt, and eggs into a stand mixer’s bowl. Mix on lowest speed with hook attachment just until combined. Pour in the melted butter/milk/sugar mixture in a slow thin stream while the mixer is going on low speed. Increase the speed to medium-high and knead for 8-10 minutes.
If proofing in oven: warm up the oven to 175 F, then turn it off. Transfer the dough into a separate greased bowl; cover with kitchen plastic, towel, and allow to rise in the warm oven or any other warm, dark place for 1.5 - 2 hours until it doubles in volume.
To make the filling: whisk together the sugars and cinnamon; set aside.
Once the dough has risen, roll it into a 1/4" thick rectangle. Evenly spread the melted butter, then the cinnamon filling. Starting from the longer end, slice the dough into 2" wide strips, then slice each strip in half leaving the top end intact. Twist the ends of each strip into a tight "rope", then roll the rope into a tight bun, tucking the end to the bottom. Place each of the buns into a greased 4" baking pans, cover with plastic and towel, and place into warm oven for 30 minutes to rise.
Once rolls have risen, bake on 350°F on middle rack for 15-18 minutes. Top with fresh strawberry pure or strawberry jam.
