• Preheat oven to 220c | 425F. Line 2x '12 muffin' muffin trays with liners or baking/parchment paper measured to fit muffin holes, and set aside.

Filling:

• In a medium-sized bowl, combine brown sugar, granulated sugar/sweetener, cinnamon, vanilla and salt. Mix well, and add in the 2 tablespoons melted butter. Mix together until well combined, and set aside.

Rolls:

• In a separate, larger bowl, whisk together the 2 1/2 cups flour, sugar, baking powder, soda and salt.
• Make a well in the centre, and pour the melted butter and 'buttermilk' into the centre, mixing them well before folding in to the rest of the ingredients. Mix gently with a wooden spoon until a dough forms. Knead mixture for about 30 seconds until smooth. If the dough is too sticky and wet to work with, add 2 tablespoons flour and knead again. (Add a little extra flour only if needed at this point, but do not go over 1/4 cup extra flour).
• Sprinkle work bench/surface with a little extra flour, coat your hands in a little flour, and shape the dough with your hands into a 13 x 10 inch rectangle. Brush the surface with 1 tablespoon of the melted butter, and spread the brown sugar mixture over the top (leaving a 1cm | 1/2-inch gap around the edges). Start rolling the dough from on the long edge until rolled to opposite end. Roll it seam side down and, using a sharp knife, cut dough into 14 equal portions.
• Place rolls into prepared muffin holes. Bake in preheated oven 20 minutes until edges are golden brown. Sprinkle chocolate chips over the tops while they're still warm.

Cream Cheese Frosting:

• Blend together cream cheese, yoghurt, sugar, vanilla and lemon until smooth and free from lumps.
• Warm frosting up in the microwave and pour over cinnamon rolls.