Heat ¾ cup for buttermilk for 40 seconds in the microwave until the liquid reaches 100-110 degrees F (38-43 degrees C). I like to do this in a liquid measuring cup. Add 1 packet of yeast and 1 tsp of granulated sugar and mix. Let it sit for 10 minutes.
Pour the mixture into the stand mixer fitted with the hook attachment. Add 6 tbsp of unsalted butter, the rest of the sugar, 1 egg, and ¼ tsp of salt. Mix together 1 tbsp of matcha powder and 3 ½ cups of all purpose flour and add it to the bowl. Make sure to sift the matcha powder to prevent clumping.
Mix the ingredients together on low (speed 2) for a minute then increase the speed to 4 to knead for 5 minutes until a green dough forms. If the dough still seems wet, add a tablespoon of flour at a time until it doesn’t stick to your hands. It can be normal to add ¼ cup to ½ cup more flour.
Cover with a wet towel or plastic wrap and let the dough rise in a warm place for 1-2 hours until it doubles in size.
Once the dough is done proofing, punch out the air. Then roll it out into a 12×12 inch square. Smear the top of the dough with 1 tbsp of unsalted butter. Top with 1/4 cup of light brown sugar and 1 tbsp of cinnamon.
Roll into a log and cut into 9 equal pieces. Cut the log into 3 equal pieces and then divide each piece into 3 equal pieces.
Place the cinnamon rolls into a greased 9×9 pan. Let the dough rise for 1-2 more hours.
Preheat the oven to 350 degrees F (177 degrees C).
After the last proof (rise), bake for 20-25 minutes uncovered until the edges are light brown.
While the cinnamon rolls are baking, make the matcha cream cheese frosting. In a stand mixer, whisk together 2 tbsp of unsalted butter, 2 oz of cream cheese, 1/4 tsp of vanilla extract, and 1 pinch of salt. Mix together 3/4 cup of powdered sugar and 3/4 tsp of matcha powder. Sift the matcha powdered sugar into the stand mixer and mix well.
Let the cinnamon rolls cool for 10 minutes before smearing on the matcha cream cheese frosting.