01 - Preheat oven to 350°F. Grease and line bottoms of three 8-inch round cake pans with parchment paper.
02 - Whisk together flour, baking powder, baking soda, and salt in a medium bowl; set aside.
03 - Beat butter and sugar with an electric mixer in a large bowl until light and fluffy, about 3 minutes. Add eggs one at a time, mixing well after each. Incorporate lemon zest, lemon juice, and vanilla extract.
04 - Add flour mixture to wet ingredients in three additions, alternating with milk, beginning and ending with flour. Mix gently until just combined to avoid overmixing.
05 - Divide batter evenly among prepared pans and smooth tops. Bake for 25–30 minutes until a toothpick inserted in center comes out clean.
06 - Allow cakes to cool in pans for 10 minutes before transferring to wire racks to cool completely.
07 - Combine raspberries, sugar, and lemon juice in a saucepan over medium heat. Stir and mash until mixture bubbles. Add cornstarch slurry and cook 1–2 minutes until thickened. Remove from heat and cool completely.
08 - Beat cream cheese and butter in a large bowl until smooth. Gradually add powdered sugar, beating until fluffy. Mix in lemon zest, lemon juice, vanilla extract, and salt until smooth.
09 - Place one cake layer on a serving plate. Spread half the raspberry filling evenly, leaving a small border. Top with second layer and repeat with remaining filling. Place third layer on top.
10 - Cover top and sides completely with lemon cream cheese frosting. Optionally decorate with fresh raspberries and lemon zest. Chill for 30 minutes before slicing.