PREPARE THE CAKE PANS: Preheat the oven to 350°F (175°C). Grease three 8-inch round cake pans and line the bottoms with parchment paper for easy removal.

WHISK DRY INGREDIENTS: In a medium bowl, whisk together the flour, baking powder, baking soda, and salt until well combined.

CREAM BUTTER, SUGAR, AND ZEST: In a large mixing bowl, beat the softened butter, granulated sugar, and lemon zest on medium speed for 3 to 4 minutes, until light and fluffy.

INCORPORATE WET INGREDIENTS: Add the eggs one at a time, beating well after each addition. Mix in the sour cream, lemon juice, and vanilla extract until fully combined.

ALTERNATE FLOUR AND MILK: Add the flour mixture in three additions, alternating with the milk and beginning and ending with the dry ingredients. Mix on low speed just until combined to avoid overmixing.

BAKE THE CAKE LAYERS: Divide the batter evenly between the prepared pans and smooth the tops. Bake for 25 to 28 minutes, or until a toothpick inserted into the center comes out clean. Let the cakes cool in the pans for 10 minutes, then turn out onto a wire rack to cool completely.

MAKE THE FROSTING: In a large bowl, beat the cream cheese and butter together until smooth. Add the lemon zest, lemon juice, vanilla extract, and salt. Gradually add the powdered sugar, one cup at a time, beating until the frosting is fluffy and spreadable.

ASSEMBLE THE CAKE: Place one cake layer on a serving plate or cake stand. Spread a thin layer of lemon cream cheese frosting over the top, followed by a few spoonfuls of raspberry jam, then scatter a handful of fresh raspberries. Repeat with the second layer. Place the third layer on top and frost the top and sides of the cake evenly. Garnish with fresh raspberries, lemon zest, and mint leaves.