Follow the directions on the box of cake mix to prepare two 8 inch cake rounds. Remove from the oven, and let cool.

While the cake is cooling, mix up the frosting. Place the whipping cream and vanilla in the bowl of an electric mixer. Whip together on a medium speed until the whipping cream starts to thicken.

Once the whipping cream has almost become whipped cream, add the powdered sugar ½ cup at a time. Mix until the frosting is slightly stiff and the powdered sugar is incorporated.

Once the cakes have completely cooled, it is time to frost the cake! I start by using a big serrated knife to trim off the rounded top of the cakes so they are flat and easier to frost.

Place the first layer of cake in the center of a cake stand. Then I cut some strips of parchment and placed them around the edge of the cake. This way when you are done you can remove the parchment and your cake stand will be all clean and won't have frosting smeared on it.

Frost the first layer of cake, and then add some whole blackberries on top. I added about a handful of blackberries. Then I added the second layer of cake on top, frosted that layer, and added more blackberries on top!

Since the frosting is made with whipped cream, don't let it sit out too long. Keep it in the fridge until dinner time. Then place it on the table for dinner and it will come to room temperature while you eat.