Preheat oven to 375 degrees F. Spray a mini muffin tin with cooking spray; set aside.
Pour flour, baking powder, sugar and salt into a large mixing bowl. Gradually stir in the buttermilk until it becomes sticky and forms a dough.
Generously flour countertop and dump out the dough onto the surface. Roll dough into a rectangle, 1/4 inch thick, sprinkling more flour as needed. (Do not use more flour than is needed to avoid a dry dough).
Spread coconut oil on rolled dough, sprinkle with 1/4 cup coconut sugar and cinnamon. Gently roll into a log, keeping the filling inside as much as possible. Using a sharp knife or dough cutter, slice into 12 rolls. Place rolls into muffin tin with the inside facing up.
Bake for 12-14 minutes until slightly browned. Cool for 5 minutes.
While cooling, stir together the Greek yogurt cream cheese, honey, and vanilla (add milk, a tablespoonful at a time, if a thinner consistency is desired).
Spread over cinnamon rolls and serve.