Pour scalded milk over 1/4 cup sugar, shortening and salt. Cool to lukewarm and sprinkle yeast into it. Beat with rotary beater until smooth. Add beaten egg and 1 1/2 teaspoons rum extract. Add half the flour and beat with rotary beater until smooth. Add remaining flour and mix until smooth. Cover with towel and let rise in a warm place (80 to 85 degrees) until double in bulk - about 3 hours. Roll dough into 2 strips, each 12 inches long, 1/2 inch thick and 4 inches wide. Brush top with melted butter and sprinkle with remaining 1/4 cup sugar and raisins. Roll up, pulling dough out at edges to keep it uniform. It should be 15 inches long when rolled. Cut rolls in crosswise slices 3/4 inch thick. Place in 3 inch greased muffin tins; cover with towel and let rise in a warm place until doubled in bulk. Bake at 400 degrees for 15 to 20 minutes. To make icing, blend confectioners sugar, hot water and rum extract. As soon as rolls are taken from oven, brush top with the icing.