Mix lukewarm water and yeast in a large bowl until the yeast is dissolved.
Add 1 egg, Greek yogurt, the butter cubes, maple syrup, and sea salt.
Mix with a wooden spoon.
Then, add in the flour a little at a time and knead into a soft dough (it will be slightly sticky).
Cover with a kitchen towel and allow it to rise for 1 hour.
Mix the ingredients for the filling.
Roll out the dough into a large rectangle on a sheet of parchment paper about 6 mm (1/4th inch) thick.
Spread the filling onto the dough.
Trim the rectangle into three symmetrical sections lengthwise.
Fold each top and bottom section towards the center so they overlap.
Pinch the dough with your fingers to seal it shut.
Repeat with the other two rectangles.
Thin out the rolls so they are 1 inch wide.
Cut the long strips into 2-3 cm (1 inch) pieces.
Arrange the rolls 2-3 cm apart (1 inch) on a lined baking sheet or two with the 'neat' side facing up.
Cover with a damp tea towel and let them rise for 1 hour.
Preheat the oven to 180°C (356°F).
Brush the rolls with egg wash.
Bake for 10 minutes until golden.
Video
Notes
If the dough seems too sticky, knead it a bit longer until it's easier to work with. If that doesn't help, add a tablespoon of flour at a time.
Keep the rolls about finger width apart on the baking sheet to prevent the filling from leaking.
Cover the rolls with a damp kitchen towel when proving.
For extra cinnamon bun flavor, top the cooled rolls with a simple glaze made with a few tablespoons of powdered sugar and a teaspoon of milk at a time until you have the perfect consistency.