Preheat oven to 350 degrees. Coat a bundt pan thoroughly with nonstick cooking spray.

In a stand mixer or using a handheld electric mixer, cream butter and sugar on high speed until fluffy. Reduce to medium speed and beat in the orange zest. Add the eggs, one at at time.

In a separate bowl, combine the orange juice, vanilla extract, milk and sour cream.

In a separate large bowl, whisk together the dry ingredients: flour, baking powder, baking soda and salt.

With the mixer running on low speed, add the flour mixture to the wet ingredients alternately with the juice mixture until combined. Pour the cake batter into the prepared pan. Bake for 45-55 minutes, until a toothpick or cake tester inserted in the center comes clean. Allow the warm cake cool completely on a wire rack before turning onto a cake plate.

Make the glaze: Combine sugar, vanilla and milk in liquid measuring cup. Whisk until smooth. Pour glaze in a back and forth motion over the top of the cake, from outside to inside. Repeat all the way around the cake.