• Grease and flour a 10 cup bundt cake pan.  Preheat oven to 350F.
• In your mixer bowl cream butter, lemon zest, and sugar together until light and well blended.
• Add eggs, beating well.
• Add lemon juice and kefir and continue beating until well mixed.
• In a separate bowl sift together flour, baking soda, and baking powder.
• Pour all at once into the liquid ingredients.
• Mix on low until just blended.
• Use a spatula to mix the last bit and ensure the batter is an even consistency.
• Pour the batter into the prepared pan.
• Bake in the middle of the oven at 350F for 30 min.  Check for doneness.
• When the cake is done removed from the oven and allow to cool for 5 minutes in the pan.
• Loosen the cake from the pan with a knife and turn on a cake plate, placed on a cooling rack.
• Allow to cool completely before icing.

Icing:

• Cream together icing sugar, zest, and butter.
• Add the lemon juice 1 tbsp. at a time beating with a whisk to blend well.
• Icing will be the consistency of thick cream.
• Pour over cooled cake, so that it drips down the sides.
• Serve at room temperature, accompanied by coffee, or tea with a twist of lemon.