In a medium bowl, gently stir together warm water, warm milk, sugar and yeast. Set aside in a warm area and let sit for 10 minutes.

In a separate large bowl, whisk together the flour, xanthan gum (if using), baking powder and salt. Set aside for now.

Add the activated yeast mixture to the dry ingredients and mix with dough hooks on low speed until the mixture starts to come together well (about 2 to 3 minutes).

Form the dough into a ball and place in a clean large bowl, lightly wetting hands if necessary.

Cover with plastic wrap and let sit for 30 to 60 minutes until it doubles in size.

Cut eight 4-inch squares of parchment paper and place on a large baking sheet.

Remove dough from bowl and place on a lightly floured surface.

Roll the dough out to a ½-inch thickness.

Cut circles out of the dough using a 3 ½-inch cookie cutter to make 8 circles.

Place dough circles onto the squares of parchment paper.

Lightly brush the tops with olive oil and fold each bun over to create half-circle shapes.

Cover the baking sheet with plastic wrap and let sit for 30 minutes.

Place buns in the bamboo steamer and fit 4 buns at a time without overcrowding.

Place about ½ inch of water in a deep frying pan or wok, bringing it to a boil then reducing heat to medium.

Place the bamboo steamer into the water, ensuring the water doesn’t touch the buns.

Cover and steam the buns over low-medium heat for 12 minutes.

Carefully remove the lid, then remove buns from steamer and repeat for remainder.

Allow buns to cool completely before storing leftovers in the fridge for up to 4 days.