Dissolve yeast in 1/4 cup warm water; let stand 5 minutes.
Place 2 cups all-purpose flour and next 5 ingredients (all-purpose flour through salt) in a food processor; pulse 4 times. Add margarine; process 10 seconds. With processor on, slowly add yeast mixture and 2/3 cup water through food chute; process until combined. With processor on, add 2 tablespoons all-purpose flour through food chute, 1 tablespoon at a time, until dough leaves sides of bowl and forms a ball. Process 15 additional seconds.
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, 45 minutes or until doubled in bulk. Punch dough down; divide into 3 equal portions. Working with one portion at a time (cover remaining dough to keep from drying), shape each portion into a 12-inch rope. Place 3 ropes lengthwise on a large baking sheet; pinch ends together at one end to seal. Braid ropes; pinch loose ends to seal. Place in an 8 x 4-inch loaf pan coated with cooking spray. Cover and let rise 45 minutes or until doubled in bulk.
Preheat oven to 375°.
Bake at 375° for 30 minutes or until loaf sounds hollow when tapped. Remove from pan immediately; cool on a wire rack.