Dissolve yeast and 1 teaspoon sugar with warm water. Let it sit until frothy, about 10 minutes. Sift the flour, salt, remaining 1 teaspoon of sugar and baking powder into a large bowl. Add the yogurt and olive oil to the yeast mixture, and stir to combine. Pour into the dry ingredients, and gently mix together with a fork. When the dough is about to come together, use your hands to mix. It will feel like there isn’t enough flour at first, but keep going until it transforms into a soft, slightly sticky and pliable dough. As soon as it comes together, stop kneading. Cover with damp towel and let it sit in a warm place for 20-30 minutes (up to 2-4 hours if you have the time). Fill a small bowl with water. Lightly dust your work surface with flour. Separate the dough into 6 equal portions, lightly roll each one in the bowl of flour. Roll each into a teardrop shape about 1/4″ thick. This can be done using your hands or using a rolling pin. Once you’ve formed the general shape, you can also pick it up by one end and wiggle it; the dough’s own weight will stretch it out a little. Repeat this method with the rest of the dough. Warm a large cast-iron skillet over high heat until nearly smoking. Make sure you have a lid large enough to fit the skillet and a dish with the melted butter ready. Dampen your hands in the bowl of water and pick up one of your naans, moistening lightly. Gently lay it in the skillet. The dough should start to bubble. Flip the naan after 1 minute. It should be blistered and somewhat blackened. Cover the skillet with the lid and cook 30 seconds to 1 minute more. Remove the naan from the skillet, drizzle with a bit of butter then spoon about a half tablespoon of minced garlic onto the naan. Place the naan in a tea towel-lined dish. Repeat with the rest of the naan and serve warm.