Make taro paste by steaming taro wedges in a steamer for 30 mins until fork tender. Mash taro with fork or masher until smooth. Add mashed taro to a pan and add coconut milk and sugar. Cook on medium low heat and stir until coconut milk and sugar are completely incorporated and thickened into a paste, about 5-10 mins. Chill to room temperature before using.
In large mixing bowl, combine ¾ cup glutinous rice flour and sugar. Mix together with boiling water until combined. Allow to rest for 5 mins until slightly cooled down. Knead in remaining glutinous rice flour and add additional 1 Tbsp water, one at a time, to form a smooth dough. Cover and rest for 10 mins.
Divide the dough into 8 even portions and roll each portion into round ball. Flatten the dough ball and add taro paste in the middle then seal the edges and roll the dough into a ball.
Quickly dip the mochi ball in water then roll the ball into a layer of sesame seeds to coat evenly.
Preheat air fryer to 200F. Add sesame balls but do not overcrowd and cook in batches if needed. Cook for 12-14 mins and flip halfway. Turn up air fryer to 350F and cook for another 5-6 mins until golden brown. Serve warm and eat immediately.
