Line a 12-cup cupcake pan with liners and preheat the oven to 350°F (180°C).

Combine the cake flour, granulated sugar, brown sugar, baking powder, baking soda, and sea salt. Mix in the cubed butter on low speed until it looks like coarse sand.

In another bowl, whisk together the hot coffee and both cocoa powders. Then, whisk in the sour cream, whole milk, egg, vegetable oil, and vanilla extract.

Mix in half of the wet ingredients into the dry ingredients on low speed until just integrated. Scrape the bowl, then mix in the rest of the wet ingredients. Scrape the bowl one last time.

Scoop the batter into the lined cupcake pan, filling each liner about 3/4 full. You should have enough batter for 12 cupcakes.

Bake the cupcakes for 18-25 minutes, or until a toothpick inserted in the center comes out with a few moist crumbs. Allow the pan to cool on a wire rack for 10 minutes, then remove the cupcakes to cool completely.

To make the frosting, cream the unsalted butter in a stand mixer until smooth.

Mix in the powdered sugar and beat on medium-low speed until light and airy.

Then, mix in the black cocoa powder, heavy cream, vanilla, and salt until combined.

Fit a piping bag with a large round tip and fill it with the frosting.

Pipe a swirl on each cupcake, roll the sides in sprinkles, and top them with eyeball candies. Enjoy!