Spray 18 regular-size muffin cups with cooking spray.
In large bowl, beat ½ cup butter, ½ cup sugar, ½ cup caramel topping, the eggs and milk with electric mixer on low speed (mixture will appear curdled).
Stir in flour, baking powder, salt, cinnamon and nutmeg just until moistened.
Divide batter evenly among muffin cups, filling each two-thirds full.
Bake 20 to 25 minutes or until toothpick inserted in center comes out clean.
Cool 5 minutes.
Meanwhile, in medium microwavable bowl, microwave ¾ cup butter on High until melted.
In small bowl, mix ¾ cup sugar and the pumpkin pie spice.