The most extraordinary moist triple-lemon Lemon Cake made by preheating oven to 350°F greasing and lining two 9-inch pans whisking 2 1/2 cups flour 2 tsp baking powder and 1/2 tsp salt beating 1 cup softened butter and 1 3/4 cups sugar medium-high 2 to 3 minutes light and fluffy adding 4 room temperature eggs one at a time then 3 tsp lemon zest 3 tbsp lemon juice and vanilla whisking 1/2 cup room temperature buttermilk and 1/4 cup room temperature sour cream on low alternating flour in 3 additions with buttermilk sour cream in 2 additions beginning and ending with flour just combined dividing between pans baking 28 to 32 minutes until toothpick clean cooling 10 minutes then on racks then beating 16 oz room temperature cream cheese and 1/2 cup room temperature butter silky smooth adding 4 to 5 cups sifted powdered sugar 3 tbsp lemon juice 1 tsp lemon zest and salt beating fluffy swirling in 1/4 cup lemon curd in 3 to 4 deliberate motions for visible swirl adding optional yellow coloring assembling with frosting between and over layers drizzling lemon curd over top decorating with lemon rounds and zest curls. A completely perfect moist buttermilk sour cream triple lemon zest juice cream cheese lemon curd frosting celebration cake recipe.