Preheat your oven to 300°F (150°C). In a mixing bowl, combine cream cheese, sugar, salt, and flour. Beat until smooth, then mix in sour cream and lemon extract. Add eggs one at a time, mixing until incorporated. Pour mixture into springform pan and bake for 45 minutes.

Turn off the oven and leave the cheesecake inside for 30 minutes. Transfer to the refrigerator for at least 4 hours until firm.

Preheat oven to 350°F (175°C) and grease two 9-inch round cake pans. Whisk together cake flour, baking powder, baking soda, salt, and lemon zest.

In a mixing bowl, cream together butter and sugar until light and fluffy. Gradually add eggs and alternate blending in dry and wet mixtures until just combined.

Divide batter between the two prepared pans and bake for 20-24 minutes or until a toothpick comes out clean. Allow cooling for 10 minutes.

Beat butter until fluffy, then add cream cheese and mix until blended. Add lemon extract and fold in powdered sugar until creamy.

Start with one lemon cake layer, spread frosting, place cheesecake layer, frost again, and add second cake layer. Frost entire cake.

Decorate with lemon zest or fruit, refrigerate for 30 minutes, slice and serve chilled.