In a medium bowl, whisk together flour, baking powder, salt, and sugar; set aside.
In the bowl of a stand mixer, whisk together milk, yogurt, oil, and egg. Add flour mixture to milk mixture and mix into a dough. With a dough hook, knead dough into a smooth ball, about 3 minutes. Remove dough onto a floured surface and clean out bowl. Lightly spray inside of bowl with cooking spray and place dough ball back inside; cover with towel; let rest for 30 minutes.
Place a baking stone on the middle oven rack; heat oven to 500°.
Divide dough into 12 pieces; cover with towel or plastic wrap. Working with 1 dough piece at a time, stretch it over a medium inverted bowl into a 6"–8" circle. Peel dough off bowl; lay on baking preheated baking stones. Bake until puffed on top, 2–3 minutes. Brush Naan with garlic butter and sprinkle with parsley, if desired.
* For garlic butter, take 1 stick of butter and place in a microwave safe bowl. Add 2 cloves of fresh minced garlic. Microwave together just until butter is completely melted. Use to brush onto hot, fresh Naan, if desired.