Mocha Mousse Slice

Australian-style layered dessert slice that shares DNA with tiramisu but isn’t trying to be Italian. Coffee-soaked sponge finger biscuits form alternating layers with a white chocolate cream filling, then the whole thing gets crowned with a rich dark chocolate mousse spiked with Kahlua.

Four distinct layers, four distinct textures: tender coffee-soaked sponge, silky white chocolate cream, more sponge, more white cream, and then the dense, fudgy dark chocolate mousse on top. It comes out of the pan as a neat rectangle, then slices into clean pieces.

Needs to chill at least overnight for the flavors to settle and the layers to firm up. Serve with a few strawberries on the side for acid and color.

Pro Tips

• Line the pan with foil with extra overhang on all sides. You’ll use those flaps to lift the whole slice out clean once it’s set.
• Brush the sponge fingers with coffee quickly, don’t soak. Over-dipped biscuits turn into sodden mush in the final slice.
• Cool the melted white chocolate and cream mixture before pouring over biscuits. Hot mixture melts the biscuits into the base.
• Whip the extra cream to firm peaks, not stiff. Over-whipped cream folds into the mousse with tiny lumps that never smooth out.

Variations

• Use ladyfingers (savoiardi) if you can’t find sponge finger biscuits, they’re essentially the same thing.
• Swap Kahlua for Tia Maria, Bailey’s, or Frangelico for different aromatic profiles.
• Top with chocolate shavings or curls instead of cocoa powder for a fancier presentation.