Preheat oven to 350 °F (175 °C). Grease two 9‑inch round cake pans, line with parchment if desired, and dust with flour.

In a large bowl, whisk together flour, cocoa powder, baking soda, baking powder, and salt.

In the bowl of a mixer, cream butter and sugar until light and fluffy (about 3 minutes), then beat in eggs one at a time and vanilla extract.

In a measuring cup, whisk together buttermilk, vegetable oil, and vinegar. Gradually add dry and wet ingredients alternately to the creamed mixture, beginning and ending with the dry. Mix just until combined. Add gel food coloring until batter reaches a soft pink hue.

Divide batter between pans and bake for 35–40 minutes, or until a toothpick inserted into the center comes out clean or with a few moist crumbs. Let cakes cool in pans 10 minutes, then transfer to wire racks to cool completely.

For the frosting, beat cream cheese and butter together until smooth. Gradually add powdered sugar, then beat in vanilla extract and a pinch of salt until creamy and spreadable.

Place one cooled cake layer on a serving plate, spread a layer of frosting, then top with the second layer. Frost the top and sides evenly. Chill the cake for about 30 minutes for a crumb coat, then add additional frosting as desired.

Decorate as desired—sprinkles, edible glitter, fresh berries or rose petals add a pretty finish. Serve at room temperature.