"Create a recipe for soft homemade pita-style flatbreads using the following ingredients and method: 3 cups all-purpose flour, 2 tsp baking powder, 1/2 tsp baking soda optional, 1 tsp fine sea salt, 1 cup warm water, 2 tbsp extra-virgin olive oil or melted butter, 1 tsp granulated sugar optional, 2 tbsp cornstarch optional, plus extra olive oil for brushing. Include clear step-by-step instructions, note that no yogurt is used, and mention optional garlic butter brushing after cooking. Use imperial units only."