In a medium bowl, whisk yeast, sugar and water until well combined. Let sit for about 10 minutes, or until yeast dissolves and begins foaming. Whisk in oil, yogurt and egg until evenly combined.
In a separate large bowl, combine 1 cup flour, salt and garlic powder. Pour wet ingredients into the flour-salt mixture and stir until well combined. Continue adding flour, 1/2 cup at a time, until you can no longer stir it with a spoon (about 1 to 1.5 cups later).
Place ball of dough onto a lightly floured surface. Knead for about 3 minutes, adding small amounts of flour to keep the dough from sticking. You'll end up using between 2.5 to 3 cups flour total. The dough should be smooth and soft, but not sticky. Avoid adding excessive amounts of flour as you knead, as this can make the dough too dry and stiff.
Loosely cover the dough with a clean kitchen towel and let rise until doubled in size (about 1-2 hours). After it rises, gently flatten the dough into a disc and cut it into 8 equal pieces. Shape each piece into a small ball. Working with one ball at a time, roll it out until it is about 1/4 inch thick or approximately 6 inches in diameter.
Heat a large skillet over medium-high heat. Place dough pieces onto the hot skillet. Cook until golden brown and large bubbles have formed on the surface, flipping once. Stack cooked flatbread on a plate and cover with a towel to keep warm.
Serve plain, or brushed with melted butter and sprinkled with fresh herbs.