For the filling: Combine coconut sugar, cinnamon, and salt in a bowl. Stir in coconut oil (or butter) and vanilla until mixture resembles wet sand; set aside.
For the dough: Grease 9-inch round cake pan. Line bottom of pan with parchment paperand grease parchment. Whisk warm milk, yeast, and coconut sugar in a bowl and let sit until bubbly about 5 minutes.
Whisk flour, baking powder, and salt together in a large bowl. Stir in yeast mixture and 2 Tbs. melted butter (or coconut oil) until dough forms. Dough will be sticky. Transfer dough to well-floured counter and knead until dough ball forms, about 2 minutes.
Roll dough into 12 by 9 inch rectangle with long side parallel to edge. Brush dough completely with 1 tablespoon melted butter, leaving ½-inch border on far edge. Sprinkle filling over butter and press filling firmly into dough. Cut dough into 8 strips. Roll each strip into a tight roll. Place each roll spiral side up. Place buns into prepared pan. I place one in the middle and 7 buns in a circle around the middle one. Cover with plastic wrap and let rise for 30 minutes, until dough springs back when gently pressed. Adjust oven rack to middle position and heat oven to 350 degrees.
Remove plastic wrap and place buns in the oven until edges are well browned - 23 to 25 minutes. Rotating pan halfway through baking. Loosen buns from sides of pan with paring knife and let cool for 5 minutes. Flip buns out of pa and then flip again, right side up, onto platter. Let cool for 5 minutes.
For the glaze: In a small mixing bowl, whisk together all glaze ingredients until smooth. Adjust consistency by adding more milk or more sugar, if needed. Drizzle glaze evenly over buns and serve.