Let butter and eggs stand at room temperature for 30 minutes. Grease and flour a 10 inch bundt cake pan and set aside.

In a medium bowl, mix flour, baking powder, baking soda and salt and set aside. In a small bowl mix milk, orange peel, lime peel and grapefruit peel; set aside.

Preheat oven to 350 degrees.

Place butter in a large mixing bowl and beat for 30 seconds with an electric mixer.

Add sugar and beat until light and fluffy. Next add eggs one at a time, beat well after each addition.

Next add vanilla.

Add flour and milk mixture by alternating on low speed until well incorporated.

Pour batter in to prepared pan and spread to form an even layer.

Place in preheated oven and bake for 40-45 minutes.

Remove from oven and cool completely before adding icing.

To make the icing, mix melted butter, orange juice and icing sugar until smooth then pour evenly over cake. Enjoy!