Preheat the oven to 365°F/ 180°C. Make a slice on the top of each fig and place on an oven tray, adding a chunk of butter into the slice and sprinkling cane sugar over the top. Place the figs into the oven for 5 minutes. Whisk the egg yolks with the sugar and the champagne. Place the mixture in a saucepan, turning the heat to low. Whip the mixture until it’s foamy and starts to thicken. This creates your sabayon. Dress the figs in a deep plate and pour the sabayon over the figs. Serve immediately.