Preheat your oven to 350°F (175°C). Grease and flour two 9-inch round cake pans.

In a large bowl, sift together the flour, sugar, cocoa powder, baking powder, baking soda, and salt.

In another bowl, whisk together the vegetable oil, buttermilk, eggs, vanilla extract, red food coloring, and vinegar.

Gradually add the wet ingredients to the dry mixture and mix until just combined. Avoid overmixing.

Pour the batter equally into prepared pans and bake for about 25-30 minutes, or until a toothpick comes out clean.

Allow the cakes to cool in the pans for 10 minutes before transferring to a wire rack. Let them cool completely before frosting.

In a large bowl, beat the softened butter until creamy. Gradually add the powdered sugar, mixing on low speed until blended.

Add the vanilla extract and heavy cream, mixing until light and fluffy.

If the frosting is too thick, add a touch more cream or a splash of milk.

Place one cake layer on a serving plate. Spread a generous amount of frosting on top, then place the second cake layer on top and frost the top and sides.

Garnish with sprinkles, fresh berries, or edible flowers if desired.