A beautifully light lemon cake with lemon buttercream frosting topped with fresh blackberries! You can use three 8" cakes pans or two 9" cakes pans depending on how many layers you want.
Preheat oven to 350 degrees and place oven rack in center position
To prevent the cake from sticking you can use non stick pans, then use a paper towel to wipe sides and bottom of pans with soft butter. Dust each pan lightly with flour, OR fold a large piece of parchment paper in half twice. Use bottom of cake pan and pencil to trace a circle on parchment, then cut folded paper so you end up with two or three circles (depending on if you are making two layers or three). Place parchment circles into the bottom of pans and spray with organic non stick spray. This is my favorite method. Set aside
Combine flour, baking powder and salt, set aside
Place butter, coconut oil, sugar and vanilla in mixer and mix until well combined
Add eggs one at a time, mixing well between additions
Alternate adding flour mixture with buttermilk until well combined, mix for one more minute
Add lemon zest and mix until incorporated (to zest lemons scrape with a microplane just until white is exposed, then move to a new area until all the yellow is gone)
Pour equal amounts of batter into prepared pans, tap pans firmly on counter to take out any bubbles
Bake for 25-30 minutes or until an inserted toothpick comes out clean
Allow cakes to cool, gently remove from pans from oven discarding parchment (if using) and then frost. You can make this cake "naked" by frosting the top of each layer, or "semi naked" by frosting each layer and then spread some frosting around the sides
Place softened butter, lemon juice, sea salt and 4 cups powdered sugar into a bowl and mix. If frosting is not quite thick enough add more sugar (up to a cup, I usually end up using almost 5 cups total). If it's too thick add just a little more juice. When frosting is desired consistency, frost cooled cake.
Right before serving: top cake with blackberries and use a screen colander or sifter to dust with powdered sugar. Add mint leaves, thyme sprigs or crushed pistachios as a garnish if desired