01 - Preheat oven to 350°F. Grease and flour three 8-inch round cake pans, lining bottoms with parchment paper for easy removal.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, and salt until well blended.
03 - Beat butter and sugar with an electric mixer on medium speed until light and fluffy, approximately 3 minutes.
04 - Add eggs one at a time, beating thoroughly after each addition. Mix in lemon zest, lemon juice, and vanilla extract until combined.
05 - Alternate adding the flour mixture and buttermilk to the batter, beginning and ending with the flour. Mix just until combined—do not overmix.
06 - Gently fold in fresh raspberries using a spatula, being careful not to crush the fruit.
07 - Divide batter evenly among prepared pans and smooth tops. Bake for 25–30 minutes, or until a toothpick inserted into the center comes out clean.
08 - Let cakes cool in pans for 10 minutes, then turn out onto wire racks to cool completely before frosting.
09 - Beat butter until creamy. Gradually add powdered sugar, lemon juice, lemon zest, salt, and cream, beating until light and fluffy. Adjust consistency with additional cream if necessary.
10 - Place one cake layer on a serving plate. Spread with frosting. Repeat with remaining layers. Frost the top and sides of the cake completely.
11 - Garnish with extra raspberries and lemon zest if desired. Refrigerate for 30 minutes before slicing to ensure clean layers.