01 - Preheat oven to 350°F. Grease and line three 8-inch round cake pans with parchment paper.
02 - In a bowl, whisk together flour, baking powder, baking soda, and salt until well combined.
03 - In a separate large bowl, beat butter, sugar, and lemon zest until light and fluffy, approximately 3-4 minutes.
04 - Beat in eggs one at a time, fully incorporating each before adding the next. Add lemon juice and vanilla extract.
05 - Alternate adding flour mixture and buttermilk to the butter mixture, beginning and ending with flour. Mix until just combined, being careful not to overmix.
06 - Divide batter evenly among prepared pans. Bake for 25-30 minutes, or until a toothpick inserted in the center comes out clean. Cool in pans for 10 minutes, then turn out onto wire racks to cool completely.
07 - Combine strawberries, sugar, and lemon juice in a saucepan. Cook over medium heat until strawberries release juices, about 5 minutes. Mix cornstarch and water, then stir into strawberries. Cook, stirring constantly, until thickened, 1-2 minutes. Remove from heat and cool completely.
08 - Beat cream cheese and butter until smooth and creamy. Gradually add powdered sugar, then lemon juice, zest, vanilla, and salt. Beat until fluffy and well combined.
09 - Place one cake layer on a serving plate. Spread half of the strawberry filling over the top, leaving a 1/2-inch border from the edge. Add a thin layer of frosting to create a dam and prevent filling from seeping out. Repeat with the second layer, then top with the final cake layer.
10 - Frost the top and sides with remaining lemon cream cheese frosting, spreading evenly. Chill cake for at least 30 minutes before slicing for neat, clean layers.