1Heat oven to 350°F. Grease 12-cup fluted tube cake pan or 10-inch angel food (tube) cake pan with shortening; lightly flour. In small bowl, mix coffee and hot water; cool 10 minutes.
2In medium bowl, mix flour, baking powder and salt; set aside. In large bowl, beat butter, sugar and eggs with electric mixer on low speed 30 seconds, scraping bowl constantly. Beat on high speed 3 minutes, scraping bowl occasionally. Beat in flour mixture, milk and sour cream on low speed until blended.
3Remove 1 cup of the batter; stir into cooled coffee. Pour remaining batter into pan. Drop coffee batter by about 12 tablespoonfuls onto batter in pan. Cut through batters with knife for marbled design.
4Bake 50 to 55 minutes or until toothpick inserted in center comes out clean. Cool 15 minutes in pan on wire rack; remove from pan to wire rack. Cool at least 1 hour 30 minutes. Serve warm or cool.