Bake at 350 degrees for 40-45 minutes or until an inserted toothpick comes out clean.
Allow cakes to cool down and then cover them in saran wrap and freeze them.
When you are ready to assemble your naked cake, remove your cakes from the freezer and allow them to sit at room temperature for 20 minutes. Then, peel off the wax paper from the bottom of the cakes.
Use a serrated knife to evenly slice the cake and remove the top dome portion.
Place a smaller cake pan (I used a dome cake pan with a width of about 7 inches) or a smaller cake board (7 inches wide) on on top of your cake.
Use a serrated knife to cut around the cake and remove the discolored top cake portion.
Follow the same steps for your second blue velvet cake too.
Place one cake on a cake stand or a serving plate.
Fill a piping bag with yellow frosting and attach Tip 1M.
Pipe a dam around the top of the cake. You can now fill the center of that dam with jam, if you like or you can just frost the inside in buttercream icing too.
Place a few blackberries evenly around the top of all that buttercream.
Place the second blue velvet cake on top of this layer of icing and blackberries.
Press the top of your cake gently so that the 2 layers of cake stick together a bit. Don't press too hard or else the icing and blackberries will shift and make a mess.
Pipe frosting around the top of your cake and you will end up will all these ruffles.
Place some more blackberries on top of the cake. Make sure to leave some space between the berries.
Now, fill the space between those berries by pushing in a few flowers and leaves and you are done. Make sure to keep this cake refrigerated until it's ready to be served. Enjoy!