Prepare grill for direct cooking. Combine 2 tbl sugar and cinnamon in small bowl; sprinkle over peach halves. Grill peaches over medium-low heat just until tender and slightly golden brown. (Peaches should still be firm and hold shape). Set aside.
Combine egg yolks, remaining 1/3 cup sugar, flour and salt in medium bowl; stir until well blended.
Bring milk, vanilla and nutmeg to a boil in medium saucepan over medium-low heat. Whisking constantly, slowly and add 1/4 cup hot milk mixture to egg yolk mixture.
Add egg yolk mixture to milk mixture in saucepan; cook, whisking constantly until thickened. Remove from heat and add butter; whisk until well blended.
Spoon sauce onto plates; arrange peach halves on top of sauce. Serve with whipped cream, if desired.
