01 - Preheat oven to 350°F. Line an 8-inch round baking pan with parchment paper or lightly grease with butter.
02 - Combine shredded mozzarella and cream cheese in a microwave-safe bowl. Microwave in 30-second bursts, stirring between intervals, until completely melted and smooth.
03 - In a large mixing bowl, whisk together almond flour, coconut flour, sweetener, baking powder, and salt until thoroughly blended.
04 - Add the melted cheese mixture and eggs to the dry ingredients. Mix with a spatula until a cohesive dough forms. Lightly oil your hands to handle the sticky dough.
05 - Place the dough between two sheets of parchment paper. Roll out into a rectangle approximately 1/4 inch thick.
06 - Stir together erythritol, cinnamon, and melted butter in a small bowl. Spread the cinnamon mixture evenly over the rolled dough surface.
07 - Using the parchment paper for assistance, roll the dough into a tight log from the long edge. Slice the log into 8 equal pieces.
08 - Arrange buns cut-side up in the prepared pan. Bake for 22-25 minutes until golden brown and set in the center.
09 - While buns bake, beat together softened cream cheese, butter, powdered erythritol, and vanilla extract. Add almond milk gradually until spreadable consistency is achieved.
10 - Remove buns from oven and cool for 10 minutes. Spread the icing generously over warm buns before serving.