Combine 1 cup flour, sugar, undissolved yeast and salt in a large mixing bowl. Heat water, milk and butter until very warm (120° to 130°F). Gradually add to flour mixture. Beat 2 minutes at medium speed of electric mixer, scraping bowl occasionally. Add egg and 1 cup flour. Beat 2 minutes at high speed. Stir in enough remaining flour to make soft dough. Knead on lightly floured surface until smooth and elastic, about 8 to 10 minutes.
Divide dough in 12 equal pieces. Roll each into 15-inch rope and loosely coil. Pinch ends firmly to seal. Place rolls on greased baking sheet. Cover; let rise in warm, draft-free place until doubled in size, about 30 to 45 minutes.
Make deep indentation in the center of rolls, fill with 1/2 teaspoon jam. Bake at 400°F for 15 minutes or until done. Drizzle with Powdered Sugar Glaze, if desired.
To make Powdered Sugar Glaze, combine powdered sugar and milk in a small bowl. Stir until smooth.