In a large bowl, whisk together the flour, protein powder, baking powder, salt, cinnamon, and coconut sugar.
Add the Greek yogurt and melted coconut oil, then stir until a soft dough forms. If the dough feels too dry, add milk or water a tablespoon at a time until it comes together.
Knead gently on a floured surface for 1–2 minutes, just until smooth.
Roll the dough into a rectangle about ¼ inch thick. Spread softened butter evenly over the surface.
In a small bowl, mix the coconut sugar and cinnamon, then sprinkle evenly over the dough.
Roll it up tightly into a log and slice into 8 even rolls.
Place the rolls in a greased 8x8-inch baking dish or parchment-lined skillet. Bake at 350°F for 20–25 minutes, until golden brown. Let cool slightly before frosting.
In a medium bowl or stand mixer bowl, beat the cream cheese until smooth. Add Greek yogurt, honey, vanilla, salt, and (optional) protein powder. Mix until thick and creamy. Spread generously over the warm, but not hot rolls.
Notes
For a thicker frosting, chill it for 10–15 minutes before spreading.