Preheat your oven to 350°F (175°C). Grease and flour the cake pans, and line the bottoms with parchment paper for easy removal.

In a large mixing bowl, cream together the softened butter and granulated sugar until light and fluffy, about 3-5 minutes.

Add the eggs, one at a time, beating well after each addition. Mix in the vanilla extract.

In another bowl, whisk together the flour, cocoa powder, baking soda, and salt. Gradually add the dry ingredients to the wet mixture, alternating with the buttermilk, starting and ending with the flour mixture. Mix until just combined.

Divide the batter evenly between the prepared cake pans and smooth the tops. Bake in the preheated oven for 25 minutes or until a toothpick inserted in the center comes out clean.

Once baked, remove from the oven and cool in the pans for 10 minutes. Then transfer to a cooling rack to cool completely.

While the cakes are cooling, prepare the berry frosting. In a mixing bowl, combine the softened butter and powdered sugar. Beat until smooth.

Gradually add the heavy cream and vanilla extract, mixing until the frosting is light and fluffy. Stir in the pureed berries until fully incorporated.

Once the cakes are completely cool, level the tops if necessary. Place one cake layer on a serving platter and spread a layer of berry frosting on top. Add a layer of fresh mixed berries.

Place the second cake layer on top and frost the entire cake with the remaining berry frosting. Decorate with additional fresh berries on top.

Slice and serve your delicious Berry Velvet Layer Cake!