To prepare buns, dissolve granulated sugar and yeast in warm milk in a large bowl; let stand 5 minutes.
Lightly spoon flour into dry measuring cups; level with a knife. Add 3 3/4 cups flour, butter, and next 3 ingredients (through eggs) to milk mixture, stirring until a soft dough forms.
Turn dough out onto a lightly floured surface. Knead in raisins. Knead dough until smooth and elastic (about 6 minutes); add enough of remaining 1/4 cup flour, 1 tablespoon at a time, to prevent dough from sticking to hands.
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 size. (Press two fingers into the dough. If indentation remains, the dough has risen enough.) Punch dough down; cover and let rest 5 minutes.
Divide dough into 20 equal portions; roll each portion into a ball. Place balls in a 9-inch square baking pan coated with cooking spray. Cover and let rise 45 minutes or until doubled in size.
Preheat oven to 350°.
Uncover and bake at 350° for 20 minutes or until golden. Cool in pan 5 minutes on a wire rack. Remove from pan.
To prepare glaze, combine powdered sugar and 1/8 teaspoon cinnamon, stirring well with a whisk. Stir in 2 tablespoons milk. Spoon glaze into a zip-top plastic bag. Seal bag; snip a tiny hole in 1 corner of bag. Pipe a cross on top of each warm roll.