Preheat oven to 350°F. Line standard 12-cavity muffin pan with cupcake liners. Set aside.

Sift together flour, baking soda, salt, and cocoa powder. Set aside.

In the bowl of a stand mixer, beat together sugar and vegetable oil. Add egg. Mix until combined.

In a separate bowl, whisk together buttermilk, red coloring, vanilla, and vinegar. Add half of liquid mixture to mixing bowl. Mix on low speed. Add half of sifted dry mixture into mixing bowl. Mix until almost combined. Then add remaining wet ingredients followed by remaining dry mixture. Mix until just combined. Scrape down bowl as needed to ensure thorough mixing.

Divide batter among prepared cupcake pan. Bake for 18-20 minutes until toothpick inserted in center of cupcakes comes out clean. Let cool in pan for 5 minutes. Gently remove cupcakes from pan and allow to cool to room temperature on wire racks.

In the bowl of a stand mixer fitted with a paddle attachment, beat together cream cheese and butter until smooth. Add vanilla. Add powdered sugar in 1 cup increments. Add pinch of salt. Mix until smooth and fluffy.

In a medium sauce pot, add frozen raspberries, sugar, lemon juice, and lemon zest. Cook over medium heat until sugar has dissolved, raspberries have thawed, and mixture has slightly thickened. Stir occasionally to prevent raspberry sauce from burning along the sides of the pot. Remove from heat. Strain out raspberry seeds. Keep raspberry coulis (sauce) in the fridge until ready to use.

Once cupcakes are cool, use an small round cookie cutter (or apple corer, melon baller, fat end of piping tip) to punch out a shallow cavity on top of each cupcake.

Prepare a piping bag with a medium star top. Place frosting in prepared bag and fill the cupcake cavity about 3/4 full. Drizzle about 2 teaspoons of cooled raspberry coulis over the frosting. Pipe a large rosette to cover the hole.

Drizzle additional raspberry coulis over frosted cupcakes. If desired, decorate finished cupcakes with royal icing knives.