for the chocolate cupcakes: Preheat oven to 350° F. Line 2 regular size cupcake pans with 24 paper liners and set aside.

In a large bowl, whisk all dry ingredients to combine. Make 3 large holes in the dry ingredients.

In a separate smaller bowl, combine oil and vinegar. Pour this into the 3 holes of the dry ingredients. Pour the water over entire mixture. Mix with a fork. Add vanilla and stir.

Divide batter evenly amongst the 24 cupcake wells. Bake for about 25 minutes, or just until a toothpick comes out clean. Remove cupcakes to wire rack to cool completely.

for the fluffy marshmallow buttercream: In the bowl of a stand mixer fitted with a paddle attachment, whip butter on medium-high speed until very fluffy, about 8 minutes, occasionally scraping down the sides and bottom of the bowl. Add powdered sugar and salt, and beat on low to incorporate. Add half and half and vanilla extract, mixing on low until combined. Increase mixer speed to medium-high and beat until very light and fluffy, about 5 minutes, occasionally scraping down the sides and bottom of the bowl. Then add marshmallow creme and mix on medium speed until just combined.

to assemble cupcakes: Use a large 4-tablespoon scoop to top each cupcake with a round of marshmallow buttercream. Gently tap the bottom of the cupcake on the counter once or twice to settle the buttercream onto the cupcake. The marshmallow buttercream recipe makes enough frosting for 24 cupcakes frosted in this generous manner. Top the marshmallow buttercream with a sprinkling of chocolate shavings.