Combine 2 cups flour, yeast, and 1 teaspoon salt in a large mixing bowl, stirring well. Combine water and 2 tablespoons olive oil in a saucepan; place over medium heat until mixture is very warm (120° to 130°).
Gradually add liquid mixture to flour mixture, beating well at low speed of an electric mixer. Beat 2 additional minutes at medium speed. Gradually stir in enough of the remaining 3/4 cup bread flour to make a soft dough.
Turn dough out onto work surface, and knead until smooth and elastic (about 10 minutes). Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85°), free from drafts, 40 minutes or until doubled in bulk.
Punch dough down; turn out onto work surface, and flatten slightly. Sprinkle currants and rosemary over dough; knead gently to incorporate currants and rosemary. Cover and let dough rest 15 minutes.
Roll dough into an 11-inch circle; place on a baking sheet sprinkled with cornmeal. Let dough rest 10 minutes. Brush dough with 1 teaspoon olive oil, and sprinkle evenly with kosher salt. Poke holes in dough at 1-inch intervals with handle of a wooden spoon. Bake at 500° for 10 to 12 minutes or until golden. Cut into wedges.