Preheat your oven to 350°F. Grease the wells of a standard 12-cup muffin tin well and set it aside.
In a medium-size, heat-safe bowl, place the chocolate and butter and melt over a double boiler or in 30-second bursts at 60% power in the microwave.
To the bowl of melted chocolate and butter, add the sugar, sour cream, eggs, and vanilla, beating to combine after each addition.
In a separate large bowl, place the flour, cocoa powder, baking powder, baking soda and salt, and whisk to combine well.
Create a well in the center of the dry ingredients, add the wet ingredients and mix to combine. The batter will be thick.
Bake and cool the cupcakes.
Fill the prepared muffin cups two-thirds full and shake the batter into an even layer in each well.
Place the pan in the center of the preheated oven and bake for about 18 minutes, or until the cupcakes are just firm to the touch.
Allow the cupcakes to cool in the muffin tin for 10 minutes before transferring to a wire rack to cool completely. Repeat with the remaining batter.
Make the filling.
If you are using heat-soluble powdered gelatin, bloom it by placing it and the water in a small, heat-safe bowl, and stirring it gently to combine.
Allow the mixture to sit at room temperature until the gelatin swells.
Place the gelatin mixture in the microwave and melt at 60% power for 20 seconds until melted. Set the gelatin aside to cool briefly.
For cold-water soluble gelatin, simply place the same amount of gelatin and the water together in a small bowl, and stir gently to combine.
In the bowl of a stand mixer fitted with the whisk attachment, or a large bowl with a hand mixer, place the chilled cream and whisk on medium speed until soft peaks form.
Add the confectioners’ sugar, and beat until stiff, glossy peaks form. Add the cooled gelatin, and beat until thickened, about 3 minutes. Makes about 4 cups of whipped cream.
Fill the cupcakes.
Once the cupcakes have cooled, create a well in the center of the bottom of each with an apple corer or 3/4-inch round cookie cutter, cutting off the bottom with a knife (reserved the removed cake pieces).
Transfer the filling to a pastry bag fitted with a 1/4-inch plain piping tip and pipe about 1 1/2 tablespoons of the prepared filling into the open well in each cake.
Cover the filling in each cake with a previously removed cake piece and press down to secure.
Place the cakes back on the wire rack over a piece of parchment or waxed paper.
Glaze the cupcakes.
Place the chocolate and coconut oil in a medium-size heat-safe bowl and melt over a double boiler or in 30-second bursts at 60% power in the microwave.
Dip the top of each cooled and filled cupcake carefully into the glaze, bob it up and down a few times to ensure that the entire top of each cake is covered in glaze, and invert back onto the wire rack.
Allow the glaze to set at room temperature.
Make the royal icing.
In the bowl of a stand mixer fitted with the paddle attachment, or a large bowl with a hand mixer, place all of the ingredients and mix on low speed until the sugar is absorbed.
Raise the mixer speed to medium, and beat until the beater leaves a visible trail in the icing, about 10 minutes.
To thicken, beat at a higher speed and for more time, and/or add more confectioners’ sugar. To thin, add more water by the quarter-teaspoonful and beat to combine.
Add the swirl once the glaze is set.
Place the royal icing in a pastry bag with a very small (#1 or #2) piping tip, and pipe a swirl across the top of the chocolate glaze.
Allow to set once again at room temperature.
Storing instructions.
These snack cakes are best enjoyed within 2 days of being glazed, but they will keep for up to a month wrapped individually in freezer-safe wrap and frozen. Defrost at room temperature. The chocolate glaze may bloom a bit over time, but it won’t affect the taste at all.