For the ice cream base: Follow the modern ice cream method. Add the wormwood essence once the base has cooled down completely.
Let the base age for at least 4 hours before churning.
Meanwhile, cut out 10 acetate rectangles measuring 11.25cm/4.5in wide by 12.5cm/5in long. They will line oval molds measuring 1.25/.5in wide by 5cm / 2.5in long by 12.5cm/5in deep. Freeze the molds on a half sheet pan lined with a nonstick rubber mat.
Churn the ice cream, fold in the cake crumbs, and then pipe it into the frozen molds. Freeze to harden. Once they are hardened, they can be pushed out of the mold and sprayed.
For the spray: Combine the chocolate coins, cocoa butter, and food coloring in a bowl and melt them over a hot water bath.
Set up a spray station, a surface that should be covered with plastic to keep the shop clean where you can spray the ice cream.
Fill a compressor canister with the chocolate spray and spray the ice cream with an even coating of spray. Keep the compressor gun at least 60cm/24in from the ice cream to obtain a velvety smooth look.
Return the sprayed ice creams to the freezer and keep them covered there during service; try to prevent whatever you use to cover them, such as plastic wrap, from coming in direct contact with them, since the spray will easily come off.
Discard after 3 days. Keep them well protected in the freezer so they do not get freezer burned or get frosted.