Preheat oven to 350°F. Line one standard 12-count muffin tin pan with liners.

In a large mixing bowl, combine flour, cocoa powder, baking soda and salt; set aside.

With a handheld or standing mixer fitted with a whisk attachment, cream together butter and sugar on high speed until light and fluffy.

Add egg and vanilla, mixing until fully combined.

Beat in oil, food coloring and vinegar until you reach the desired color.

With the mixer on low, add dry ingredients alternately with buttermilk. Mix until just combined, being sure not to overmix batter.

Evenly distribute batter into prepared pan.

Bake for 15 to 18 minutes or until toothpick inserted in center comes out clean.