First, in a bowl, combine the milk, sugar, yeast and mix gently. Cover the bowl and set it aside for 10 minutes. If the mixture bubbles, it means the yeast is active. If the mixture doesn't bubble, then repeat this step with new yeast.
In a separate bowl, whisk together the flours, salt, baking powder, and xanthan gum. Then add to it the egg, apple cider vinegar, and the milk yeast mixture.
Using a stand-alone mixer with the paddle attachment at low-medium speed or by hand, form the dough and knead it. Once the dough is combined, add in the butter and mix/knead again.
Once the dough has come together and is smooth and sticky, transfer it to a greased bowl and cover it with a damp tea towel. Allow the dough to rise for at least two hours.
Next, remove the dough and divide it into eight equal balls. Each ball will weigh approximately 100 grams.
Using a rolling pin, roll each ball into a stretched oval, as seen below. The dough should have a thickness of at least 3 mm. If the dough is sticky, then sprinkle flour on your rolling surface and rolling pin.
Then, brush the dough with garlic butter paste assuring that the garlic paste is evenly distributed.
Then starting from the left-hand corner, gently start rolling the dough as seen below.
Then close the two ends together by pressing on them.
Brush each garlic bread flower with olive oil and allow them to rest for another 20 minutes.
Preheat the oven to 180℃.
Bake the bread for about 20-25 minutes or until the edges are golden.