Place 1 tablespoon melted Isomalt into one half-sphere mold with the brown food coloring. Stir half-heartedly, then, using the bottom of your spoon, press the Isomalt up the sides of the mold.
Press one of the empty Isomalt cups open-side-down onto the flat portion of the warm plate for about 10 seconds.
This will gently melt the rim of the cup.Immediately press this warmed edge Isomalt cup to the top of one of the filled cups.