Preheat oven to 400°.
Lightly spoon flour into dry measuring cups; level with a knife. Combine flour, cornmeal, and next 4 ingredients in a large bowl. Cut in butter with a pastry blender or 2 knives until mixture resembles coarse meal. Stir in cheese. Add milk and egg, stirring just until moist.
Turn dough out onto a lightly floured surface, and knead 3 or 4 times. Transfer dough to a baking sheet coated with cooking spray; pat into a 7-inch circle. Cut into 10 wedges, cutting to, but not through, bottom of dough. (Do not separate wedges.)
Bake at 400° for 17 minutes or until golden. Transfer scones to a wire rack. Serve warm.