Combine together the water, sugar and yeast. Let sit for 5-10 minutes or until the mixture begins to bubble on top
Add in the milk, yogurt, oil, flour baking powder and salt. Mix until the dough comes together with your hands.
Turn dough out onto lightly floured surface. Use floured hands to knead the dough until smooth, about 3 to 5 minutes.
Lightly grease the same mixing bowl with a small spray of cooking oil. Transfer dough to the bowl and cover with plastic wrap. Let rest at room temperature for about an hour until doubled in size.
When ready to cook, divide the dough into 10 equal pieces. Roll into balls, then use a rolling pin to roll each piece of dough into a large oval, about 6-inches long and 1/8-inch thick. Repeat with remaining dough.
Heat a large cast iron skillet over medium-high heat. Grease skillet all over with 1/2 teaspoon of the extra oil.
Place one piece of the naan on the oiled hot skillet and cook until bubbles form on top, about 1-2 minutes. While cooking, brush the top with a little oil.
Flip and cook for another 1-2 minutes, until large golden spots appear on the bottom.
Remove from the skillet and wrap in a clean kitchen towel. Repeat with the remaining naan (keep them wrapped in a towel while you work).