Preheat oven to 325 degrees and grease and sugar a bundt pan
Zest four lemons.
Remove the peel from the lemons by cutting it away vertically. Next holding the lemon over a bowl, supreme each lemon by cutting each segment on either side of the membrane to remove the flesh. When done make sure to remove any seeds and break up the lemon segments in the juice
Combine the sugar and lemon zest in a small bowl and mix with your fingers until the sugar becomes moist and grainy.
In a mixing bowl beat the butter for two minutes. Add half the sugar/lemon mixture, beat again for two minutes then add the remaining sugar/lemon mixture; beat for four minutes. Make sure to scrape the bowl occasionally.
Add the eggs to the above mixture one at a time, beating each just until combined.
On the lowest setting beat in the dry ingredients.
Beat in the sour cream.
Fold in the lemon segments and the juice.
Pour the batter into your prepared pan. Bake about 1 1/2 hours until cake tester at the center of the cake comes out clean. Let cool and turn out the cake to cool.
Making the glaze
In a small bowl add the powdered sugar. Zest and juice one lemon and add this to the powdered sugar and stir until smooth.