Heat oven to 450°. Coat two large baking sheets with nonstick cooking spray; set aside.
Stir together mozzarella, yogurt, Parmesan, bread crumbs, oregano and 1/4 teaspoon of the salt and the pepper; set aside.
Heat a large nonstick skillet over medium-high heat. Crumble sausage into skillet and cook 6 minutes or until no longer pink. Add broccoli rabe, garlic, water, red pepper flakes and remaining 1/4 teaspoon salt to pan and cook, stirring constantly, for 3 minutes or until broccoli rabe has wilted. Remove from heat, cool 10 minutes then stir together with yogurt mixture.
Divide dough into 6 pieces. On a floured surface, roll each piece into a 7-inch circle. Place a heaping 1/2 cup of filling onto one half of each circle. Fold dough over filling; press edges together firmly to seal. Cut 3 slits through tops. Repeat with remaining dough and filling.
Carefully place calzones on prepared baking sheets and bake for 15 minutes or until lightly browned. Cool 10 minutes before serving.