1. Preheat oven to 375°F.
2. Combine 1 cup flour, undissolved yeast, sugar and salt in a large bowl. Add very warm water and oil; mix until well blended, about 1 minute. Gradually add enough remaining flour to make a soft dough. Dough should form a ball and will be slightly sticky. Knead** on a floured surface, adding additional flour if necessary, until smooth and elastic, about 4 minutes. Cover and let rest on floured surface while preparing fillings.
3. To make calzones, divide dough into four portions. Roll 1 portion into an 8-inch circle on a floured surface. Spread desired fillings on bottom half of dough, leaving outer 1/2-inch free of filling. Fold top half of dough over filling. Pull edge of lower crust over top; folding and pressing layers together to form a seal. Carefully transfer to greased baking sheet. Cut 3 to 4 vents in top. Repeat with remaining dough. Bake for 15 to 20 minutes until lightly browned. Transfer to cooling rack to keep bottom crust crisp while cooling slightly. Serve with pizza sauce or other sauce for dipping.
4. Recipe Tip: For a crisper crust, brush calzones with olive oil and sprinkle with coarse salt just before baking.

*If you don't have a thermometer, water should feel very warm to the touch.

**To knead the dough, add just enough flour to the dough and your hands to keep the dough from sticking. Flatten dough and fold it toward you.Using the heels of your hands, push the dough away with a rolling motion. Rotate dough a quarter turn and repeat the "fold, push and turn" steps. Keep kneading dough until it is smooth and elastic. Use a little more flour if dough becomes too sticky, always working the flour into the ball of dough.