To make the cake:
Combine the flour, baking powder and salt and sit to the side.
Then, using a hand or stand mixer, beat the butter and sugar together on medium speed until creamy (approximately 2 minutes).
Next, add the lemon instant pudding and mix until combined.
Add the eggs to the bowl one at a time, mixing well after each addition before adding the next egg.
Next, add the lemon juice and mix.
Using a spoon or spatula scrape down the sides of the bowl and mix ensuring that the batter is fully mixed together.
Mix in the flour 1/2 c to 1 c at a time, alternating with the sour cream, beginning and ending with the flour.
Spray a 12 cup bundt pan with non-stick spray. Pour the batter into the pan and spread it evenly.
Set the oven to 325 degrees and bake for about an hour and 15 minutes. The cake is done once an inserted toothpick comes out clean.
Remove the cake from the oven and allow it to cool for about 20 minutes before inverting.
Allow the cake to continue to cool on a wire rack before adding the glaze.
To make the glaze:
Using a hand or stand mixer, mix the powdered sugar, lemon juice, and milk until well blended and the desired consistency is reached.
Decorate the cake with the glaze as desired and serve. (The cake can be iced while it is still warm.)
Serve and enjoy!