This elegant dessert has a sweet secret: layers of chocolaty richness nestled in a shell of almond sponge cake.
Line ring molds with acetate, secure with tape, and place on a parchment-lined baking sheet. Line interior of each mold with a strip of joconde cake, piped side facing out (trim strips to fit exactly into the mold if needed; the ends should meet). Brush interior of joconde strips with espresso syrup. Brush bottoms of chocolate joconde cake rounds with syrup, and fit one, syrup side up, into bottom of each mold.
Pipe a layer of ganache (about 1 tablespoon) onto chocolate joconde rounds, and smooth with a small spoon.
Pipe Bavarian cream onto ganache layers, filling each mold about two-thirds full.
Pipe a layer of ganache (about 1 tablespoon) onto Bavarian cream, and then top with a chocolate jocande round, syrup side down. Refrigerate until cream is firm, at least 4 hours (or up to 12 hours).
To glaze cakes before serving, carefully unmold, remove acetate, and place on a wire rack set over a piece of parchment. Using a small spoon, pour just enough glaze on each cake to cover top (about 1 tablespoon per cake); do not let it drip down sides. Let stand until set, 20 to 30 minutes. Garnish with meringue.