Mix cake mix and pudding together, add oil, water, eggs and sour cream. Add in 1Tbs of lemon juice and 1Tbs of lemon rind.
Pour into greased and floured pans. Bake at 350 for 30-45 minutes depending on cake size. If you use ten inch pans for a whole recipe like I do, bake at 325 for 50-55 minutes. Check for with toothpick or wood skewer to test for doneness.
Cool cake completely. I usually wrap the cakes up in a tea towel or several layers of paper towels and let them cool in the fridge as this helps to keep the cake moist.
Filling: Into a small bowl mix all but 1 Tbs of the lemon curd (reserve for frosting) Add in 1 Tbs of lemon juice. Spread filling over bottom layer of cake, place second layer on top.
Frosting: Whip both pints of whipping cream until peaks begin to form, gently fold in confectioner's sugar, 1Tbs lemon curd and 1Tbs lemon rind. Blend well being careful not over blend--the frosting should be light and fluffy.
Frost cake and let set for at least two hours before serving.