FOR THE CAKE:

Preheat the oven to 350 degrees.

Grease and flour three 6" round baking pans and line the bottoms with parchment paper. You may also use two 8" round pans, if desired. Set aside.

Place the flour, salt, baking powder, and baking soda in a mixing bowl and whisk together. Set aside.

Place the sugar, lemon zest, and butter in a large mixing bowl. Cream with an electric mixer until light and airy, about 2 minutes.

Beat in the eggs, on at a time.

Add the vanilla and lavender oil and beat in.

Mix the buttermilk and lemon juice together.

Beat in the flour and buttermilk/lemon juice in alternating batches, mixing until just combined.

Fold in the flour coated blackberries.

Divide the batter evenly between the prepared pans.

Bake in the preheated oven for 20-25 minuets, or until a tester inserted into the center comes out clean. Let cook completely, then turn out on a wire rack.

FOR THE FROSTING:

Place the butter, cream cheese, and vanilla in a large bowl and beat together.

Slowly beat in the powdered sugar until a smooth frosting forms. Beat in a little bit of milk, if needed for a smooth, spreadable consistency.

TO ASSEMBLE:

Spread a thin layer of cream cheese frosting on two of the cake layers. Stack all three cake layers on top of each other on a serving dish.

Frost the tops and sides of the cake with the remaining frosting.

Decorate as desired.