Preheat oven to 180C.
Grease and line a round 24cm cake pan.
Place butter and sugar into mixing bowl and cream on high speed with electric mixer until light and fluffy.
Reduce speed and add eggs one at a time, then add vanilla and bourbon.
Sift flour and salt together. (Or combine them in a large bowl and whisk for 20 seconds with a balloon whisk.)
With mixer at low speed add flour and buttermilk slowly, alternating between the two. Combine well.
Stir the ginger through.
Pour mixture into prepared pan and bake 40-45 minutes.
Test by piercing the centre of the cake with a skewer. Cake is cooked if skewer comes out dry.
Combine all ingredients with a mixer until smooth and creamy.
Frost cake when it is cool.