01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper cupcake liners.
02 - In a medium mixing bowl, whisk together all-purpose flour, granulated sugar, unsweetened cocoa powder, baking soda, and salt until evenly distributed.
03 - In a large mixing bowl, whisk together vegetable oil, buttermilk, eggs, vanilla extract, white vinegar, and red food coloring until thoroughly combined and uniform in color.
04 - Gradually add the dry ingredient mixture to the wet mixture, stirring gently until just combined. Avoid overmixing to maintain a tender crumb structure.
05 - Divide batter evenly among the prepared cupcake liners, filling each approximately two-thirds full.
06 - Bake for 18 to 20 minutes, or until a toothpick inserted into the center of a cupcake emerges clean with no wet batter.
07 - Allow cupcakes to cool in the muffin tin for 5 minutes, then transfer to a wire cooling rack to cool completely before frosting.
08 - In a clean mixing bowl, beat softened cream cheese and softened unsalted butter together using an electric mixer until smooth and well combined.
09 - Gradually add sifted powdered sugar to the cream cheese mixture, beating on medium speed until light and fluffy. Mix in vanilla extract and salt until incorporated.
10 - Pipe or spread frosting generously onto each cooled cupcake. Decorate with heart-shaped sprinkles, fresh berries, or garnish of choice.