Arrange a rack in the middle of the oven and heat to 350°F. Line two muffin pans with 24 cupcake liners.

Whisk the sugar, flour, cocoa, baking powder, baking soda, and salt together in the bowl of a stand mixer fitted with the paddle attachment or a large mixing bowl. Add the egg, milk, oil, and vanilla, then beat with the stand or hand mixer on medium speed until well-combined, about 2 minutes. Beat in the boiling water. The batter will be quite thin. Divide the batter evenly between the wells in the pan, filling each no more than 3/4 full.

Bake until a toothpick inserted in the center of the cupcakes comes out clean, 15 to 18 minutes. Cool the cupcakes in the tin for about 5 minutes, then transfer the cupcakes to a cooling rack to cool completely.

Meanwhile, place the cream in a clean, cold large bowl of a stand mixer fitted with the whisk attachment. Beat the cream with the stand or a hand mixer on high speed until soft peaks develop, about 3 minutes. Add the sugar, vanilla, and gelatin if using and continue beating until stiff peaks form, 2 to 3 minutes more. Place the whipped cream in the refrigerator until you’re ready to assemble the cupcakes.

Once the cupcakes are completely cooled, use a paring knife to slice into the top of each cupcake, cutting a cone about 1 1/2 inches in diameter out of the center, without cutting through the bottom of the cupcake. Spoon the cherry pie filling into the center of each cupcake.

Transfer the whipped cream to a pastry bag fitted with a round tip and pipe onto the cupcakes. Top each cupcake with a fresh cherry and chocolate shavings.