Line a shallow baking dish with greaseproof (wax) paper.
For the honeycomb, combine the sugar, honey, syrup and one tbsp of water in a saucepan over a medium heat, stirring until you see the sugar dissolve. Keep an eye on it as it simmers, stirring gently all the time. Continue stirring until the mixture forms a caramel, turning a golden brown colour like warm honey.
Remove from the heat and have the lined dish ready, as the next step will happen quickly.
Add the bicarbonate of soda (baking soda). The mixture will start to froth, so pour it immediately into the lined dish, then set aside for about 15 minutes, or until cool to touch. Once cool, break it into pieces.
Melt the chocolate in a heatproof bowl set over a pan of simmering water, making sure the bottom of the bowl doesn’t touch the water, then stir in most of the honeycomb pieces, reserving a few for decoration.
In a separate bowl, gently stir the cream into the mascarpone. Then stir two-thirds of the mix into the chocolate mix until just marbled. Spoon into small glasses or cups and top with the remaining cream mix and honeycomb pieces.