Combine warm water, yeast, and sugar. Let sit for 5-10 minutes until foamy.
Whisk 3 cups flour with salt and baking powder. Add yeast mixture, yogurt, oil, and minced garlic. Mix until shaggy dough forms.
Knead on floured surface for 8-10 minutes until smooth and elastic.
Place dough in oiled bowl, cover, and let rise in warm place for 1-1½ hours until doubled.
Mix melted butter, minced garlic, cilantro, and salt. Let sit to infuse.
Punch down dough, divide into 8-10 balls. Cover and rest 10 minutes.
Roll each ball into ¼-inch thick oval or teardrop shape about 6-8 inches long.
Heat cast iron skillet over medium-high heat for 5 minutes until very hot.
Place naan in dry hot skillet. Cook 1-2 minutes until bubbles form and bottom has golden-brown spots.
Flip and cook 1-2 minutes more until second side has golden spots and naan puffs up.
Remove from skillet and immediately brush generously with garlic butter.
Repeat with remaining dough. Stack finished naan covered with towel to keep warm. Serve immediately.