Stir together icing sugar and whipping cream in a small bowl. Pour into an ungreased 9x13-inch baking pan. Spread pecans over the mixture. Set aside.

On a lightly floured surface, roll each loaf into an 8x12-inch rectangle. Brush with melted butter. Mix brown sugar and cinnamon together in a small bowl, and sprinkle over the loaves. Top with raisins.

Roll up rectangles, starting at the long 12-inch side. Pinch each end closed. Cut each roll into 6 pinwheels, and place slices, cut side down, on top of the pecan mixture. Cover with a towel and let rise in a warm place until nearly double in size (about 30 minutes).

To make ahead, cover rolls with greased waxed paper and then plastic wrap (instead of a towel). Refrigerate for 2 to 24 hours. The rolls will rise while in the refrigerator.

Bake in 375°F oven, uncovered, until golden - 25 to 30 minutes for unchilled rolls, OR 30 to 35 minutes for chilled rolls.

Check on rolls while they bake, and if necessary, cover them with aluminum foil during the last 10 minutes of baking to prevent overbrowning.

Remove from oven and let rest for 5 minutes. Loosen rolls from pan edges. Place large serving plate on top of pan and invert plate so that rolls are released from the pan.

Serve warm!