I've only ever had these as single cookies without chocolate, but here goes. Sorry about the approximate measures.
250g dessicated coconut
1 cup flour
1 small tin condensed milk (215mL?)
1. Preheat oven to 180C
2. Put coconut in a large bowl, and sift flour into it. Mix.
3. Pour condensed milk into bowl, and mix. You want the mixture to be sticky, but not too wet, or the cookies will not hold their shape. Err on the side of dry.
4. Line a baking tray with baking paper, and put large spoonsful of mixture onto tray. Mine are usually 3-4cm diameter.
5. Bake for 15-20 minutes, or until golden brown.
6. Let cool on rack.
If you want to make them into sandwiches, flatten the cookies a bit before baking. When they are cool, melt some chocolate in a double boiler, and smear it on the bottom of one cookie, then join it with another. Personally, I'd find this too sweet, but I love having my macaroons with black coffee