Preheat the oven to 350°F (175°C) and prepare two 6-inch cake pans by greasing with butter and lining with parchment paper.

In a large mixing bowl, cream the softened butter until smooth, then gradually add the white sugar and beat until light and fluffy.

Add the vegetable oil, room temperature egg, vanilla extract, and white vinegar to the mixture, and beat until fully combined.

In a separate bowl, whisk together the all-purpose flour, cocoa powder, baking soda, and salt. Mix half into the wet ingredients until just combined.

Pour in the buttermilk and mix well, then add the remaining dry ingredients and beat until smooth.

Add the red gel food coloring and gently mix until the color is evenly distributed.

Divide the batter between the prepared pans and bake for 22-25 minutes or until a toothpick comes out clean.

Remove the cakes from the oven and cool in the pans for 10 minutes before transferring to wire racks to cool completely.

In a mixing bowl, beat the softened cream cheese, powdered sugar, and vanilla until smooth for the frosting.

Whip the heavy cream until stiff peaks form, then fold into the cream cheese mixture until fully incorporated.

Tint ½ cup of frosting red and frost the top of one cake layer, placing the second layer on top and frosting the entire cake.

Use the reserved red frosting to pipe mini hearts or other decorations.