Preheat oven to 350 Degrees (F).
Grease and flour (lightly) two 9 inch round cake pans (I also used parchment paper cut to fit).
Mix all ingredients together by hand for 30 seconds. Beat at medium speed for 2 minutes.
Pour batter evenly into pans.
Bake for 25-30 minutes (do the toothpick trick in testing to see if the cakes are done) and cool. After cakes have cooled for 10 minutes, remove and place on cooling rack (flip one layer over)
While the cake is cooling add the softened butter and cream cheese to a large mixing bowl and beat on high for 2 minutes until light and fluffy.
Add in the powdered sugar, vanilla, lemon juice, and lemon zest and continue to mix on med/high for 3-5 minutes or until fluffy and fully combined.
Frost the top of one layer first with half of the buttercream frosting.
Place the top layer on to the bottom layer and gently push down on the top layer and twist until the frosting on the middle layer looks even.
Frost the top layer with the remaining frosting.