Preheat the oven to 350 degrees F.
Prepare two 9 inch cake pans. Cut out 2 circles of parchment paper. Flip the pan upside down and trace a circle of parchment paper. Cut out the circle.
Spray both pans with nonstick cooking spray. Insert the parchment paper circles and spray the circles. Set aside.
Use a stand mixer with paddle attachment and beat together the butter, brown sugar, granulated sugar, lemon zest and vanilla extract. Beat for 5-6 minutes until the mixture is light and fluffy. Make sure to scrape down the sides of the bowl.
Next, add the eggs one at a time. Beat until combined.
Combine the cake flour and baking powder in a separate mixing bowl.
Once combined, add the dry ingredients into the wet ingredients and mix together on low speed until just combined. Be careful not to over mix the batter.
Add the sour cream, milk and lemon juice. Use low speed and beat until just mixed together. Do not over mix the batter.
Use a small mixing bowl and combine the fresh raspberries with all-purpose flour to prevent the fruit from sinking to the bottom of the cake.
Gently fold in the flour coated raspberries into the batter by hand. Do not overmix.
Pour the batter evenly between the 2 prepared cake pans.
Bake for 35-40 minutes until the tops are lightly golden brown and a toothpick inserted in the center comes out clean.
Allow the cakes to cool in the pans for 8-10 minutes. Then gently use a butter knife to loosen the edges of the cake from the pan. Place the cakes on a cooling rack to finish cooling.
While the cakes cool, make the frosting.