Preheat the oven to 350°F (175°C). Grease and flour the three 9-inch round cake pans.
In a large mixing bowl, cream the softened butter and granulated sugar together until light and fluffy (about 4-5 minutes).
Add the eggs one at a time, mixing well after each addition, followed by the vanilla extract.
In another bowl, combine the flour, baking powder, baking soda, cocoa powder, and salt.
Gradually add the dry ingredients to the butter mixture, alternating with the milk. Mix until just combined. Add red food coloring for color, if desired.
Divide the batter evenly among the three prepared cake pans.
Bake in the preheated oven for 25-30 minutes or until a toothpick inserted in the center comes out clean. Let the cakes cool in the pans for 10 minutes before transferring them to a cooling rack to cool completely.
While the cakes are cooling, prepare the frosting. In a large mixing bowl, whip the heavy cream, powdered sugar, and vanilla extract until stiff peaks form.
Once the cakes are completely cooled, place one layer on a cake stand. Spread a generous amount of frosting on top and sprinkle with a handful of fresh berries.
Add the second layer of cake, repeat the frosting and berry layering, and then place the final layer on top.
Frost the top and sides of the cake with the remaining whipped cream and decorate with additional fresh berries.
Slice and serve the cake chilled or at room temperature.