Heat oven to 350ºF. Grease tart pan with removable bottom, about 9x1 inch, or springform pan, 9x3 inches. Mix Bisquick, powdered sugar and pecans in medium bowl. Cut in butter, using pastry blender or crisscrossing 2 knives, until mixture looks like fine crumbs. Stir in hot water. Press mixture firmly in bottom of tart pan.